{ "name": "GenetixBay Knowledge Base", "version": 1, "generated": "2026-10-31T13:44:58Z", "url": "https://genetixbay.com/knowledge/", "license": { "name": "CC BY-SA 4.0", "url": "https://creativecommons.org/licenses/by-sa/4.0/", "attribution": "GenetixBay Knowledge Base (genetixbay.com/knowledge)" }, "count": 146, "evidence_ladder": [ { "id": "established", "name": "Established", "meaning": "Multiple studies or extension consensus" }, { "id": "supported", "name": "Supported", "meaning": "Some research or strong grower consensus" }, { "id": "grower_practice", "name": "Grower practice", "meaning": "Widely used, little research" }, { "id": "contested", "name": "Contested", "meaning": "Evidence points both ways" }, { "id": "myth", "name": "Myth", "meaning": "Widely believed, not supported by evidence" } ], "categories": [ { "id": "basics", "name": "Basics", "description": "Plant biology, life cycle, photoperiod vs auto, sex, first grows", "url": "https://genetixbay.com/knowledge/basics/", "count": 8 }, { "id": "germination", "name": "Germination", "description": "Seed viability, germination, seedlings, damping-off, transplanting", "url": "https://genetixbay.com/knowledge/germination/", "count": 5 }, { "id": "environment", "name": "Environment", "description": "Temperature, humidity, VPD, airflow, CO₂ and light", "url": "https://genetixbay.com/knowledge/environment/", "count": 10 }, { "id": "nutrients", "name": "Nutrients", "description": "Every element, deficiencies and toxicities, feed schedules, recipes", "url": "https://genetixbay.com/knowledge/nutrients/", "count": 25 }, { "id": "ph-ec", "name": "pH and EC", "description": "pH, EC and ppm scales, water quality, runoff, drift", "url": "https://genetixbay.com/knowledge/ph-ec/", "count": 7 }, { "id": "systems", "name": "Systems", "description": "Soil, coco, rockwool, living soil and every hydro system", "url": "https://genetixbay.com/knowledge/systems/", "count": 16 }, { "id": "training", "name": "Training", "description": "Topping, LST, SCROG, SOG, mainlining, defoliation", "url": "https://genetixbay.com/knowledge/training/", "count": 8 }, { "id": "pests", "name": "Pests", "description": "Identification, life cycles, thresholds and IPM", "url": "https://genetixbay.com/knowledge/pests/", "count": 8 }, { "id": "diseases", "name": "Diseases", "description": "Mildew, botrytis, root rot, viruses and viroids, sanitation", "url": "https://genetixbay.com/knowledge/diseases/", "count": 7 }, { "id": "diagnosis", "name": "Diagnosis", "description": "Symptom-led decision trees: start here when something looks wrong", "url": "https://genetixbay.com/knowledge/diagnosis/", "count": 15 }, { "id": "harvest-cure", "name": "Harvest and cure", "description": "Ripeness, flushing evidence, drying, curing, storage", "url": "https://genetixbay.com/knowledge/harvest-cure/", "count": 6 }, { "id": "breeding", "name": "Breeding", "description": "Genetics, pollination, selection, stabilisation, seed production", "url": "https://genetixbay.com/knowledge/breeding/", "count": 21 }, { "id": "genetics-history", "name": "Genetics history", "description": "Landraces, heritage lines and lineages, with evidence labels", "url": "https://genetixbay.com/knowledge/genetics-history/", "count": 10 } ], "articles": [ { "id": "kb-basics-buyer-beware-label-claims", "title": "Buyer beware: potency labels, strain names and other claims that don't hold up", "category": "basics", "category_name": "Basics", "slug": "buyer-beware-label-claims", "url": "https://genetixbay.com/knowledge/basics/buyer-beware-label-claims.html", "markdown_url": "https://genetixbay.com/knowledge/basics/buyer-beware-label-claims.md", "summary": "Flower labelled above about 35% total cannabinoids is not credible: cannabinoids are made only in trichome heads, and bud is mostly bract, stem and leaf, so numbers like that belong to concentrates or to inflated testing. Studies show potency results vary systematically between labs, and retail flower labels often overstate THC. Be equally sceptical of strain names that promise effects, terpene totals far above the ~2% average, and 'indica for the couch, sativa for energy'.", "tags": [ "potency", "thc", "labels", "lab-testing", "lab-shopping", "terpenes", "strain-names", "indica", "sativa", "consumer", "buyer-beware" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Is 40% THC flower real?", "Is most dispensary weed really 30% THC?", "What THC does retail flower really test at?", "Have regulators caught inflated THC labels?", "What is the highest THC cannabis flower can have?", "Are cannabis THC labels accurate?", "What is lab shopping?", "Why does the same strain test differently at different labs?", "Is a high terpene percentage on the label believable?", "Do indica strains make you sleepy and sativas energetic?", "Does a strain name guarantee the effect?", "Can seeds really hit 42% THC?", "How is total THC calculated?", "Does frosty weed mean high THC?", "Is purple weed stronger?", "Can you judge cannabis quality by looks?", "What is bag appeal?" ], "myths": [ "Most shelf weed is 30 %", "Flower can test 35 %, even 42 %, total cannabinoids", "Humidity packs keep your stash fresher", "Frost and purple mean potency" ], "related": [ "kb-diagnosis-purple-stems-leaves", "kb-environment-temperature-by-stage", "kb-genetics-history-why-strain-names-are-unreliable", "kb-genetics-history-indica-sativa-ruderalis", "kb-harvest-cure-trichome-ripeness", "kb-breeding-chemotype-inheritance" ], "sources_count": 17, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-basics-glossary", "title": "Cannabis growing and breeding glossary", "category": "basics", "category_name": "Basics", "slug": "glossary", "url": "https://genetixbay.com/knowledge/basics/glossary.html", "markdown_url": "https://genetixbay.com/knowledge/basics/glossary.md", "summary": "Plain-language definitions of the growing, botany and breeding terms used across GenetixBay, with notes where the popular meaning differs from the scientific one.", "tags": [ "glossary", "terminology", "definitions", "breeding-terms", "grow-terms" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "beginner", "qa": [ "What does F1 mean in cannabis?", "What is a phenotype vs a genotype?", "What is an IBL?", "What does S1 mean?", "What is a clone-only?", "What is a chemotype or chemovar?", "What does BX mean?" ], "myths": [], "related": [ "kb-basics-cannabis-plant-biology", "kb-breeding-mendelian-genetics-for-growers", "kb-breeding-f1-f2-f3-explained", "kb-breeding-backcrossing-ibl-stabilisation", "kb-breeding-documenting-lineage-evidence" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-basics-cannabis-plant-biology", "title": "Cannabis plant biology: the parts and what they do", "category": "basics", "category_name": "Basics", "slug": "cannabis-plant-biology", "url": "https://genetixbay.com/knowledge/basics/cannabis-plant-biology.html", "markdown_url": "https://genetixbay.com/knowledge/basics/cannabis-plant-biology.md", "summary": "Cannabis sativa is a fast-growing annual herb in the hemp family. Most plants are either male or female, it flowers in response to long nights (unless it carries autoflower genetics), and the cannabinoids and terpenes growers want are made in glandular trichomes concentrated on the female flower heads.", "tags": [ "botany", "anatomy", "trichomes", "cannabinoids", "dioecy", "roots", "leaves" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "beginner", "qa": [ "What are the parts of a cannabis plant?", "Where are THC and terpenes made in the plant?", "What is a trichome?", "Is cannabis a male and female plant?", "What is the difference between a calyx, a bract and a pistil?", "How many chromosomes does cannabis have?" ], "myths": [], "related": [ "kb-basics-buyer-beware-label-claims", "kb-basics-life-cycle", "kb-basics-sex-male-female-hermaphrodite", "kb-basics-photoperiod-vs-autoflower", "kb-basics-glossary", "kb-breeding-chemotype-inheritance" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-basics-sex-male-female-hermaphrodite", "title": "Male, female and hermaphrodite cannabis: how sex works", "category": "basics", "category_name": "Basics", "slug": "sex-male-female-hermaphrodite", "url": "https://genetixbay.com/knowledge/basics/sex-male-female-hermaphrodite.html", "markdown_url": "https://genetixbay.com/knowledge/basics/sex-male-female-hermaphrodite.md", "summary": "Cannabis is dioecious: females are XX and males XY, and the species has kept separate sexes stably for millennia. Hermaphrodite (intersex) plants are unwanted outliers, mostly the result of bad breeding such as repeated selfing, careless feminising and untested seed; stress reveals the weakness in susceptible plants. Cull herm-prone plants and never breed from them. Seed from a female's own male flowers is almost all female, which is how feminised seed works and why herm tendency passes straight on.", "tags": [ "sex", "male", "female", "hermaphrodite", "intersex", "XY", "pre-flowers", "nanners", "dioecious", "breeding-ethics" ], "stage": [ "veg", "transition", "flower" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "beginner", "qa": [ "How do I tell a male from a female cannabis plant?", "What is a hermaphrodite cannabis plant?", "Are hermaphrodites natural in cannabis?", "What are bananas or nanners on my bud?", "Does stress cause hermaphrodites?", "Can I test seedling sex early?", "Are seeds from a hermie plant all female?" ], "myths": [], "related": [ "kb-basics-cannabis-plant-biology", "kb-diagnosis-hermaphrodites", "kb-breeding-feminised-seed-sex-reversal", "kb-breeding-s1-selfing", "kb-breeding-selection-pheno-hunting", "kb-breeding-pollination-seed-production" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-basics-photoperiod-vs-autoflower", "title": "Photoperiod vs autoflower, and how autoflowering is inherited", "category": "basics", "category_name": "Basics", "slug": "photoperiod-vs-autoflower", "url": "https://genetixbay.com/knowledge/basics/photoperiod-vs-autoflower.html", "markdown_url": "https://genetixbay.com/knowledge/basics/photoperiod-vs-autoflower.md", "summary": "Photoperiod cannabis flowers when nights get long; autoflowering (day-neutral) cannabis flowers by age, even under 18-24 h light. In the populations studied so far, autoflowering behaves as a single recessive gene (Autoflower1, on chromosome 1): a photoperiod x auto F1 is all photoperiod, and about 1 in 4 of its F2 plants are autos.", "tags": [ "autoflower", "photoperiod", "day-neutral", "ruderalis", "Autoflower1", "inheritance", "recessive" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "What is the difference between autoflower and photoperiod?", "Is the autoflower gene dominant or recessive?", "If I cross an auto with a photoperiod, what do I get?", "Can I grow autos on 12/12?", "What light schedule for autoflowers?", "Why did my autoflower not flower?", "Are autos better than photoperiods?", "Do autos yield more per year?", "Are autoflowers less potent?", "Are autoflowers good for beginners?" ], "myths": [ "Autos are easy" ], "related": [ "kb-breeding-breeders-vs-pollen-chuckers", "kb-training-sog", "kb-training-scrog", "kb-germination-transplanting", "kb-training-lst", "kb-basics-life-cycle" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-basics-seed-types-regular-feminised-auto-clone", "title": "Regular, feminised, autoflower or clone: choosing your starting material", "category": "basics", "category_name": "Basics", "slug": "seed-types-regular-feminised-auto-clone", "url": "https://genetixbay.com/knowledge/basics/seed-types-regular-feminised-auto-clone.html", "markdown_url": "https://genetixbay.com/knowledge/basics/seed-types-regular-feminised-auto-clone.md", "summary": "Regular seed gives about half males and is what breeders need; feminised seed gives nearly all females and suits growers who want flower; autoflowers flower by age; clones copy one known plant but can carry pests and viroids. Each choice changes what you can do next.", "tags": [ "regular-seed", "feminised-seed", "autoflower", "clones", "starting-material", "seed-pack" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Should I buy regular or feminised seeds?", "Are feminised seeds more likely to hermie?", "Are clones better than seeds?", "What does a seed pack's GB-PKG code mean?", "Can I breed with feminised seeds?" ], "myths": [], "related": [ "kb-basics-sex-male-female-hermaphrodite", "kb-diagnosis-hermaphrodites", "kb-basics-first-grow-guide", "kb-basics-photoperiod-vs-autoflower", "kb-breeding-feminised-seed-sex-reversal", "kb-breeding-clone-only-preservation" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-basics-life-cycle", "title": "The cannabis life cycle, stage by stage", "category": "basics", "category_name": "Basics", "slug": "life-cycle", "url": "https://genetixbay.com/knowledge/basics/life-cycle.html", "markdown_url": "https://genetixbay.com/knowledge/basics/life-cycle.md", "summary": "Cannabis goes from seed to seedling (1-3 weeks), vegetative growth (2-8+ weeks indoors, set by the grower for photoperiod plants), transition, flowering (about 7-12 weeks for most drug-type cultivars, longer for some tropical types) and ripening, then harvest, drying and curing. Photoperiod plants flower when nights are long enough; autoflowers flower by age.", "tags": [ "life-cycle", "germination", "seedling", "vegetative", "flowering", "harvest", "photoperiod" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "beginner", "qa": [ "How long does it take to grow cannabis from seed?", "What are the stages of cannabis growth?", "When does cannabis start flowering?", "How long is the vegetative stage?", "What is the stretch in early flower?" ], "myths": [], "related": [ "kb-basics-cannabis-plant-biology", "kb-basics-photoperiod-vs-autoflower", "kb-basics-first-grow-guide", "kb-basics-sex-male-female-hermaphrodite", "kb-environment-photoperiod-light-leaks", "kb-germination-germination-methods" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-basics-first-grow-guide", "title": "Your first grow: a plan from seed to jar", "category": "basics", "category_name": "Basics", "slug": "first-grow-guide", "url": "https://genetixbay.com/knowledge/basics/first-grow-guide.html", "markdown_url": "https://genetixbay.com/knowledge/basics/first-grow-guide.md", "summary": "For a first indoor grow, use one to four plants of a reputable feminised autoflower or photoperiod line in a tent, a good LED, quality soil or coco, a pH and EC meter, and a journal. Keep the targets simple: steady temperature and humidity, light to about 400-600 µmol/m²/s in veg and 600-900 in flower, water by weight, and harvest by trichomes.", "tags": [ "first-grow", "beginner", "setup", "lighting", "watering", "feeding", "harvest", "journal" ], "stage": [ "any" ], "systems": [ "soil", "coco" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "What do I need for my first cannabis grow?", "Should a beginner grow autoflowers or photoperiods?", "How much light does cannabis need?", "How often should I water my plants?", "Soil or coco for a first grow?", "What temperature and humidity should my tent be?" ], "myths": [], "related": [ "kb-harvest-cure-flush-debate", "kb-basics-life-cycle", "kb-basics-photoperiod-vs-autoflower", "kb-basics-seed-types-regular-feminised-auto-clone", "kb-basics-sex-male-female-hermaphrodite", "kb-germination-germination-methods" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-germination-damping-off", "title": "Damping-off: why seedlings collapse at the soil line", "category": "germination", "category_name": "Germination", "slug": "damping-off", "url": "https://genetixbay.com/knowledge/germination/damping-off.html", "markdown_url": "https://genetixbay.com/knowledge/germination/damping-off.md", "summary": "Damping-off is seedling death caused mainly by soil-borne pathogens such as Pythium, Rhizoctonia and Fusarium: the stem pinches, darkens and collapses at the soil line, or seeds rot before emerging. It is a prevention problem: clean containers and new mix, no overwatering, warm medium, good light and airflow. Once a seedling has collapsed it cannot be saved.", "tags": [ "damping-off", "pythium", "rhizoctonia", "fusarium", "seedlings", "sanitation" ], "stage": [ "seedling" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "beginner", "qa": [ "Why did my seedling fall over at the base?", "What is damping off and how do I prevent it?", "Can a damped-off seedling be saved?", "Does cinnamon stop damping off?" ], "myths": [], "related": [ "kb-germination-seedling-care", "kb-germination-germination-methods", "kb-environment-humidity-by-stage", "kb-environment-airflow", "kb-diseases-sanitation-and-prevention", "kb-diseases-root-rot-pythium" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-germination-germination-methods", "title": "Germination methods compared: soak, paper towel, plugs, direct sow", "category": "germination", "category_name": "Germination", "slug": "germination-methods", "url": "https://genetixbay.com/knowledge/germination/germination-methods.html", "markdown_url": "https://genetixbay.com/knowledge/germination/germination-methods.md", "summary": "Cannabis seed germinates best around 20–30 °C (68–86 °F) with steady moisture and air. Every common method works if those are met: direct sowing is least handling, paper towels let you see radicles, plugs and cubes suit hydro. Lab protocols with 1 % hydrogen peroxide, short soaks or tip scarification sped up germination, mainly for old or hard seeds; they are optional for fresh seed.", "tags": [ "germination", "paper-towel", "soaking", "hydrogen-peroxide", "scarification", "rockwool", "plugs" ], "stage": [ "seedling" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "What is the best way to germinate cannabis seeds?", "Should I soak seeds before planting?", "Does hydrogen peroxide help germination?", "What temperature for germinating cannabis seeds?", "How deep do I plant a cannabis seed?", "How long should germination take?" ], "myths": [], "related": [ "kb-germination-seed-viability-storage", "kb-germination-seedling-care", "kb-germination-damping-off", "kb-germination-transplanting" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-germination-seed-viability-storage", "title": "Seed viability and storage: keeping cannabis seeds alive", "category": "germination", "category_name": "Germination", "slug": "seed-viability-storage", "url": "https://genetixbay.com/knowledge/germination/seed-viability-storage.html", "markdown_url": "https://genetixbay.com/knowledge/germination/seed-viability-storage.md", "summary": "Cannabis seeds stay viable longest when dry and cold: research on hemp and drug-type seeds recommends about 5 °C (41 °F) storage to keep germination ability for around six years, with low seed moisture and an airtight container. Room temperature and humid storage cost viability within months to a few years. Test old seeds with a small germination test before planting a whole batch.", "tags": [ "seeds", "storage", "viability", "germination-test", "refrigerator", "freezer", "moisture" ], "stage": [ "seedling" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "How long do cannabis seeds last?", "Should I store seeds in the fridge or freezer?", "How do I know if my seeds are still viable?", "Do dark seeds germinate better than pale ones?", "Can I revive old cannabis seeds?" ], "myths": [], "related": [ "kb-germination-germination-methods", "kb-germination-seedling-care", "kb-germination-damping-off", "kb-breeding-seed-germination-testing-qc" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-germination-seedling-care", "title": "Seedling care: the first three weeks", "category": "germination", "category_name": "Germination", "slug": "seedling-care", "url": "https://genetixbay.com/knowledge/germination/seedling-care.html", "markdown_url": "https://genetixbay.com/knowledge/germination/seedling-care.md", "summary": "Seedlings need moderate light (about 150–300 µmol/m²/s, 18 h, a DLI of 10–19 mol/m²/day), warm and fairly humid air (23–27 °C / 73–81 °F, 65–75 % RH), and small, careful waterings. Most seedling losses come from overwatering, too little light (stretching) or damping-off, not from lack of nutrients. Start feeding lightly once the first two or three sets of true leaves have formed.", "tags": [ "seedlings", "stretching", "watering", "light", "humidity", "first-feed" ], "stage": [ "seedling" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Why is my seedling stretching and falling over?", "How much should I water seedlings?", "How far should the light be from seedlings?", "When should I start feeding seedlings?", "What humidity for cannabis seedlings?" ], "myths": [], "related": [ "kb-germination-germination-methods", "kb-germination-damping-off", "kb-germination-transplanting", "kb-environment-ppfd-dli-by-stage", "kb-environment-vpd-explained", "kb-diagnosis-stretching" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-germination-transplanting", "title": "Transplanting: when, into what, and avoiding transplant shock", "category": "germination", "category_name": "Germination", "slug": "transplanting", "url": "https://genetixbay.com/knowledge/germination/transplanting.html", "markdown_url": "https://genetixbay.com/knowledge/germination/transplanting.md", "summary": "Transplant when roots fill the current container but before they circle: typically seedling plug to 1–3 L at 2–3 weeks, then to the final pot 2–4 weeks before flowering. Move the root ball intact into pre-moistened medium at the same pH and similar EC, water in lightly, and keep light and climate gentle for a few days. Autoflowers do best sown straight into their final pot.", "tags": [ "transplanting", "potting-up", "root-bound", "transplant-shock", "container-size" ], "stage": [ "seedling", "veg" ], "systems": [ "soil", "coco", "rockwool", "living_soil" ], "evidence": "grower_practice", "evidence_name": "Grower practice", "level": "beginner", "qa": [ "Does pot size limit yield?", "When should I transplant my cannabis seedling?", "What size pots should I transplant into?", "How do I avoid transplant shock?", "Can I transplant during flower?", "Should I transplant autoflowers?" ], "myths": [], "related": [ "kb-training-lst", "kb-germination-seedling-care", "kb-systems-soil", "kb-systems-coco", "kb-systems-rockwool", "kb-germination-damping-off" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-environment-airflow", "title": "Airflow: air exchange, canopy air speed and fan placement", "category": "environment", "category_name": "Environment", "slug": "airflow", "url": "https://genetixbay.com/knowledge/environment/airflow.html", "markdown_url": "https://genetixbay.com/knowledge/environment/airflow.md", "summary": "Aim for gentle, constant movement across and under the canopy (roughly 0.3–1.0 m/s at leaf level) plus enough exhaust to remove heat and humidity, typically one full tent air exchange every 1–3 minutes for a lit tent. Moving air thins the leaf boundary layer, which raised canopy photosynthesis in non-cannabis research, and dries out the microclimates where mould starts.", "tags": [ "airflow", "fans", "exhaust", "ventilation", "boundary-layer", "carbon-filter" ], "stage": [ "seedling", "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "How many fans do I need in a grow tent?", "How fast should air move over cannabis leaves?", "What size exhaust fan for my tent?", "Can too much wind hurt plants?", "Should fans run at night?" ], "myths": [], "related": [ "kb-environment-vpd-explained", "kb-environment-humidity-by-stage", "kb-environment-co2-enrichment", "kb-environment-heat-light-stress" ], "sources_count": 3, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-environment-co2-enrichment", "title": "CO₂ enrichment: when it pays, how much, and how to stay safe", "category": "environment", "category_name": "Environment", "slug": "co2-enrichment", "url": "https://genetixbay.com/knowledge/environment/co2-enrichment.html", "markdown_url": "https://genetixbay.com/knowledge/environment/co2-enrichment.md", "summary": "Raising CO₂ from ambient (~420 ppm) to 800–1,200 ppm during lights-on raises cannabis photosynthesis substantially, but only pays when light is already high (roughly 900+ µmol/m²/s) and the room is sealed enough to hold it. Keep occupied rooms below the 5,000 ppm 8-hour workplace limit and never enter a room above 30,000 ppm.", "tags": [ "co2", "enrichment", "photosynthesis", "safety", "sealed-room" ], "stage": [ "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Is CO2 worth it for a small grow tent?", "What ppm CO2 should I run in flower?", "Do I need CO2 above 1000 PPFD?", "Is CO2 dangerous to people?", "Should CO2 run at night?" ], "myths": [], "related": [ "kb-environment-ppfd-dli-by-stage", "kb-environment-temperature-by-stage", "kb-environment-airflow", "kb-environment-heat-light-stress" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-environment-heat-light-stress", "title": "Heat and light stress: taco leaves, bleaching and foxtails", "category": "environment", "category_name": "Environment", "slug": "heat-light-stress", "url": "https://genetixbay.com/knowledge/environment/heat-light-stress.html", "markdown_url": "https://genetixbay.com/knowledge/environment/heat-light-stress.md", "summary": "Heat and light stress show at the top of the plant, closest to the light: leaves curl up or taco, bracts bleach white or yellow, buds may foxtail. Measure leaf temperature and canopy PPFD before blaming nutrients. Typical fixes: dim or raise the light 10–20 %, bring leaf temperature under about 30 °C (86 °F), restore airflow and root-zone water uptake.", "tags": [ "heat-stress", "light-stress", "bleaching", "foxtailing", "tacoing", "light-burn" ], "stage": [ "veg", "flower", "ripen" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Why are my top leaves curling up like tacos?", "Why are my top buds turning white?", "Is it light burn or nitrogen toxicity?", "What causes foxtailing?", "How far should my LED be from the canopy?" ], "myths": [], "related": [ "kb-environment-ppfd-dli-by-stage", "kb-environment-temperature-by-stage", "kb-environment-vpd-explained", "kb-environment-airflow", "kb-environment-co2-enrichment", "kb-diagnosis-taco-canoeing-leaves" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-environment-humidity-by-stage", "title": "Humidity by stage: RH targets from clone to cure", "category": "environment", "category_name": "Environment", "slug": "humidity-by-stage", "url": "https://genetixbay.com/knowledge/environment/humidity-by-stage.html", "markdown_url": "https://genetixbay.com/knowledge/environment/humidity-by-stage.md", "summary": "Run about 65–80 % RH for clones and seedlings, 55–70 % in veg, 50–60 % early flower and 40–50 % in late flower, adjusted to hit a leaf VPD band at your temperature. High RH in flower raises bud-rot and mildew risk and, in a 2025 study, delayed flowering and lowered cannabinoids. Dry and cure near 60 % RH.", "tags": [ "humidity", "rh", "botrytis", "powdery-mildew", "dehumidifier", "dew-point" ], "stage": [ "seedling", "veg", "transition", "flower", "ripen", "harvest", "cure" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "What humidity should I have in flower?", "Is 70 % humidity too high in late flower?", "Why does humidity spike when the lights go off?", "How big a dehumidifier do I need?", "Can low humidity increase trichomes?" ], "myths": [], "related": [ "kb-environment-vpd-explained", "kb-environment-temperature-by-stage", "kb-environment-airflow", "kb-harvest-cure-drying", "kb-germination-seedling-care", "kb-diseases-botrytis-bud-rot" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-environment-light-spectrum", "title": "Light spectrum: blue, red, far-red and UV, what's real", "category": "environment", "category_name": "Environment", "slug": "light-spectrum", "url": "https://genetixbay.com/knowledge/environment/light-spectrum.html", "markdown_url": "https://genetixbay.com/knowledge/environment/light-spectrum.md", "summary": "Photon quantity (PPFD/DLI) and fixture efficacy matter far more than spectrum. Less blue slightly increased cannabis yield (about 12 % from 4 % to 20 % blue). Far-red stretches plants; its yield effect is contested and seems to trade off against cannabinoid concentration. UV has repeatedly failed to raise cannabinoids in controlled trials and can cut yield at high doses.", "tags": [ "spectrum", "far-red", "uv", "blue-light", "led", "hps" ], "stage": [ "veg", "flower" ], "systems": [ "any" ], "evidence": "contested", "evidence_name": "Contested", "level": "intermediate", "qa": [ "Does UV light increase THC?", "Is far-red worth adding to my LED?", "What spectrum is best for flowering cannabis?", "Do I need a different spectrum for veg and flower?", "Is a full-spectrum white LED as good as HPS?", "Do LEDs need more Cal-Mag?" ], "myths": [ "UV-B lamps raise THC" ], "related": [ "kb-environment-ppfd-dli-by-stage", "kb-environment-photoperiod-light-leaks", "kb-environment-heat-light-stress", "kb-nutrients-cal-mag", "kb-environment-vpd-explained" ], "sources_count": 8, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-environment-photoperiod-light-leaks", "title": "Photoperiod and light leaks: 18/6, 12/12 and the dark period", "category": "environment", "category_name": "Environment", "slug": "photoperiod-light-leaks", "url": "https://genetixbay.com/knowledge/environment/photoperiod-light-leaks.html", "markdown_url": "https://genetixbay.com/knowledge/environment/photoperiod-light-leaks.md", "summary": "Photoperiod cannabis stays vegetative under long days (18/6 up to 24/0; no sleep period is needed in veg) and flowers when the uninterrupted night is long enough: 12/12 or 13/11, and some cultivars flower at 14–15 h, usually as ~12 h at high intensity plus sunrise and sunset ramps. Light during the dark period, even very dim, can delay or weaken flowering in sensitive cultivars; leaks can also expose herm-prone genetics, triggering male flowers on susceptible plants. Some cultivars yield more at 13–14 h days, at a possible cost in THC concentration.", "tags": [ "photoperiod", "12-12", "light-leak", "night-interruption", "flowering", "autoflower", "hermaphrodite" ], "stage": [ "veg", "transition", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Why is my plant not flowering on 12/12?", "How dark does the grow room need to be at night?", "Do light leaks cause hermaphrodites?", "Can I flower on 13/11 or 14/10?", "Can I run 24/0 in veg?", "Do sunrise and sunset ramps count as daylight?", "What photoperiod for autoflowers?" ], "myths": [], "related": [ "kb-environment-ppfd-dli-by-stage", "kb-environment-light-spectrum", "kb-environment-heat-light-stress", "kb-diagnosis-hermaphrodites", "kb-environment-flip-to-flower-transition" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-environment-ppfd-dli-by-stage", "title": "PPFD and DLI by stage, with the evidence", "category": "environment", "category_name": "Environment", "slug": "ppfd-dli-by-stage", "url": "https://genetixbay.com/knowledge/environment/ppfd-dli-by-stage.html", "markdown_url": "https://genetixbay.com/knowledge/environment/ppfd-dli-by-stage.md", "summary": "In the best indoor trial, cannabis flower yield rose linearly with canopy PPFD from 120 to 1,800 µmol/m²/s at ambient CO₂ (116 to 519 g/m²) with no change in cannabinoid potency. Practical targets: 100–300 µmol/m²/s for seedlings and clones, 300–700 (up to ~900) in veg, and 800–1,200 in flower, or more with CO₂, as long as the plant shows no stress and the electricity is worth it.", "tags": [ "ppfd", "dli", "light-intensity", "led", "yield", "par" ], "stage": [ "seedling", "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "What PPFD should I run in flower?", "What DLI does cannabis need?", "Does more light increase THC?", "Is 1500 PPFD too much without CO2?", "How do I convert PPFD to DLI?", "What PPFD for seedlings and clones?" ], "myths": [], "related": [ "kb-environment-co2-enrichment", "kb-environment-light-spectrum", "kb-environment-photoperiod-light-leaks", "kb-environment-heat-light-stress", "kb-germination-seedling-care" ], "sources_count": 7, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-environment-temperature-by-stage", "title": "Temperature by stage: day, night and root-zone targets", "category": "environment", "category_name": "Environment", "slug": "temperature-by-stage", "url": "https://genetixbay.com/knowledge/environment/temperature-by-stage.html", "markdown_url": "https://genetixbay.com/knowledge/environment/temperature-by-stage.md", "summary": "Run roughly 24–28 °C (75–82 °F) by day in veg, 22–26 °C (72–79 °F) in flower, cooling to 20–24 °C (68–75 °F) in late flower, with nights 3–6 °C (5–10 °F) cooler. Above about 30 °C (86 °F) photosynthesis in cannabis falls unless light and CO₂ are high. Keep the root zone and hydro reservoirs at 18–22 °C (64–72 °F).", "tags": [ "temperature", "day-night", "dif", "root-zone", "reservoir", "climate" ], "stage": [ "seedling", "veg", "transition", "flower", "ripen" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "What temperature should my grow room be in veg and flower?", "How much cooler should the night be?", "Is 30 °C too hot for cannabis?", "What reservoir temperature should I run?", "Does a cold night really bring out purple colour?", "Do cold nights increase terpenes?" ], "myths": [ "Cold nights boost terpenes and resin" ], "related": [ "kb-environment-vpd-explained", "kb-environment-humidity-by-stage", "kb-environment-co2-enrichment", "kb-environment-heat-light-stress", "kb-systems-dwc", "kb-diagnosis-stretching" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-environment-flip-to-flower-transition", "title": "The flip isn't day 1 of flower: the 10–14 day transition and how to count it", "category": "environment", "category_name": "Environment", "slug": "flip-to-flower-transition", "url": "https://genetixbay.com/knowledge/environment/flip-to-flower-transition.html", "markdown_url": "https://genetixbay.com/knowledge/environment/flip-to-flower-transition.md", "summary": "Switching to 12/12 starts floral induction, not flowering. In controlled studies the first visible inflorescence (at least three pairs of pistils at the top of the main shoot) appeared roughly 8–14 days after short days began, around 13–14 days on average across many hemp cultivars, and up to three weeks in slow ones. Breeder flowering times often count from that point, so a stated 8 weeks usually means harvest about 9.5–10 weeks after the flip. Count both: days since flip and days of flower.", "tags": [ "flip", "12-12", "transition", "floral-induction", "pistils", "preflowers", "stretch", "critical-photoperiod", "flowering-time", "harvest-timing", "journal" ], "stage": [ "veg", "transition", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Is the first day of 12/12 the first day of flower?", "How long after the flip do pistils show?", "Why does my strain take longer than the breeder says?", "When does flowering actually start after switching to 12/12?", "Are preflowers the start of flowering?", "How do I count weeks of flower?", "How long does the stretch last?", "How will I know my plant is really flowering?", "Does 13/11 delay flowering?" ], "myths": [ "Day 1 of 12/12 is day 1 of flower" ], "related": [ "kb-environment-photoperiod-light-leaks", "kb-basics-life-cycle", "kb-basics-first-grow-guide", "kb-harvest-cure-trichome-ripeness", "kb-diagnosis-stretching", "kb-basics-photoperiod-vs-autoflower" ], "sources_count": 10, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-environment-vpd-explained", "title": "VPD explained: vapour pressure deficit for cannabis growers", "category": "environment", "category_name": "Environment", "slug": "vpd-explained", "url": "https://genetixbay.com/knowledge/environment/vpd-explained.html", "markdown_url": "https://genetixbay.com/knowledge/environment/vpd-explained.md", "summary": "VPD is how hard the air pulls water out of the leaf, in kPa. Common targets are about 0.4–0.8 kPa for seedlings and clones, 0.8–1.2 kPa in veg and 1.0–1.5 kPa in flower, calculated from leaf temperature rather than air temperature. Most of these bands come from grower and greenhouse practice; cannabis-specific VPD trials are still scarce.", "tags": [ "vpd", "humidity", "temperature", "transpiration", "leaf-temperature", "climate" ], "stage": [ "seedling", "veg", "flower", "ripen" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "What is VPD and why does it matter for cannabis?", "What VPD should I run in veg and flower?", "How do I calculate VPD with leaf temperature?", "What humidity do I need at 26 °C to hit 1.2 kPa?", "Is leaf VPD or air VPD the right number?", "My VPD is perfect but plants still look stressed, why?" ], "myths": [], "related": [ "kb-environment-humidity-by-stage", "kb-environment-temperature-by-stage", "kb-environment-airflow", "kb-environment-heat-light-stress", "kb-germination-seedling-care", "kb-diagnosis-taco-canoeing-leaves" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-bloom-boosters", "title": "\"Bloom boosters\" for cannabis: what's real and what's marketing", "category": "nutrients", "category_name": "Nutrients", "slug": "bloom-boosters", "url": "https://genetixbay.com/knowledge/nutrients/bloom-boosters.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/bloom-boosters.md", "summary": "Most bloom boosters are concentrated phosphorus and potassium. Four independent controlled cannabis trials found no increase in flower yield or cannabinoids from raising phosphorus above roughly 25–60 mg/L, and one found no yield response to potassium anywhere from 60 to 340 mg/L. A complete, balanced flower feed is what matters; extra P and K mostly end up in the runoff and can induce magnesium, calcium, zinc and iron problems. Some boosters have been reported to contain undeclared plant growth regulators, which have no place in a consumable crop.", "tags": [ "bloom-booster", "pk-booster", "phosphorus", "potassium", "flowering", "additives", "plant-growth-regulators", "myths" ], "stage": [ "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Do bloom boosters work on cannabis?", "Should I use a PK booster in week 4 or 5 of flower?", "Does high phosphorus increase bud size?", "Are bloom boosters a waste of money?", "What is in a bloom booster?", "Are there growth regulators in some cannabis additives?" ], "myths": [ "High-phosphorus bloom boosters mean bigger buds" ], "related": [ "kb-nutrients-phosphorus", "kb-nutrients-potassium", "kb-nutrients-feed-by-stage", "kb-nutrients-nutrient-antagonism", "kb-nutrients-magnesium", "kb-nutrients-zinc" ], "sources_count": 7, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-boron", "title": "Boron (B) in cannabis: distorted tips, dying roots and a narrow safe window", "category": "nutrients", "category_name": "Nutrients", "slug": "boron", "url": "https://genetixbay.com/knowledge/nutrients/boron.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/boron.md", "summary": "Boron cross-links cell-wall pectin and is needed wherever cells are dividing: shoot tips, root tips and flowers. Deficiency in cannabis causes stunted, distorted new growth, dead growing tips and wilting from root-tip death; toxicity scorches the margins of older leaves. Supply about 0.2–0.5 mg/L B; cannabis tolerated a tenfold dose for weeks but the gap between enough and too much is narrower than for most nutrients.", "tags": [ "boron", "micronutrient", "deficiency", "toxicity", "immobile-nutrient", "cell-wall", "roots" ], "stage": [ "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "What does boron deficiency look like in cannabis?", "Why are my growing tips twisted and dying?", "How much boron in hydroponic solution?", "Can boron be toxic to cannabis?", "Why is my plant wilting even though the medium is wet?" ], "myths": [], "related": [ "kb-nutrients-calcium", "kb-nutrients-mobile-vs-immobile-nutrients", "kb-ph-ec-water-quality", "kb-diagnosis-yellow-new-growth", "kb-diagnosis-drooping-overwatering-vs-underwatering" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-feed-by-stage", "title": "Building a cannabis feed by stage: ppm targets per element and how to hit them", "category": "nutrients", "category_name": "Nutrients", "slug": "feed-by-stage", "url": "https://genetixbay.com/knowledge/nutrients/feed-by-stage.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/feed-by-stage.md", "summary": "A good mineral cannabis feed runs roughly N 150–200, P 30–60, K 175–250, Ca 150–200, Mg 40–70 and S 60–120 mg/L in veg and flower, plus Fe 1.5–3 and small amounts of Mn, Zn, B, Cu and Mo, at an EC of about 1.2–1.8 mS/cm in veg and 1.6–2.2 in flower. Cannabis research shows no benefit from pushing P or overall strength higher. This article gives the targets, the evidence behind each, and two worked RO-water recipes with a sources table.", "tags": [ "feed-chart", "recipe", "ppm", "ec", "veg", "flower", "seedling", "diy-nutrients", "hydro", "coco" ], "stage": [ "seedling", "veg", "transition", "flower", "ripen" ], "systems": [ "dwc", "rdwc", "nft", "ebb_flow", "drip", "coco", "rockwool", "aero" ], "evidence": "supported", "evidence_name": "Supported", "level": "advanced", "qa": [ "How many ppm of each nutrient does cannabis need in veg and flower?", "What EC should I run for cannabis in veg and flower?", "How do I make my own cannabis nutrients from salts?", "What is a good N-P-K ratio for flowering cannabis?", "Do I need to change nutrients between veg and flower?", "What EC for seedlings and clones?" ], "myths": [], "related": [ "kb-nutrients-hydroponic-salts", "kb-nutrients-nitrogen", "kb-nutrients-phosphorus", "kb-nutrients-potassium", "kb-nutrients-calcium", "kb-nutrients-magnesium" ], "sources_count": 10, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-cal-mag", "title": "Cal-Mag: what it is, when you need it and when you don't", "category": "nutrients", "category_name": "Nutrients", "slug": "cal-mag", "url": "https://genetixbay.com/knowledge/nutrients/cal-mag.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/cal-mag.md", "summary": "Cal-Mag is a calcium and magnesium supplement, usually calcium nitrate and magnesium nitrate, sometimes with iron. You need it when your water and base nutrient together supply too little Ca and Mg: RO or very soft water, new or unbuffered coco, or a base nutrient designed for hard water. How much a plant needs is driven mainly by its cultivar, the water source, the medium (coco's cation exchange), root-zone pH and transpiration. The claim that LED lights create a Cal-Mag need is a myth. You do not need it on hard tap water with a complete base feed, and overusing it adds nitrogen and pushes potassium and magnesium out of balance.", "tags": [ "cal-mag", "calcium", "magnesium", "ro-water", "coco", "led", "supplements" ], "stage": [ "veg", "flower" ], "systems": [ "coco", "dwc", "rdwc", "nft", "drip", "rockwool", "soil" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Do I need Cal-Mag with RO water?", "How much Cal-Mag should I use in coco?", "Do LED lights need more Cal-Mag?", "Why does one strain need Cal-Mag and another doesn't in the same room?", "I switched from HPS to LED and got rust spots: is it Cal-Mag?", "Can I use too much Cal-Mag?", "Should I add Cal-Mag if I have hard tap water?", "Is Cal-Mag the same as Epsom salt?" ], "myths": [ "LED lights make plants need Cal-Mag" ], "related": [ "kb-nutrients-calcium", "kb-nutrients-magnesium", "kb-ph-ec-water-quality", "kb-ph-ec-buffering-coco", "kb-nutrients-feed-by-stage", "kb-nutrients-nutrient-antagonism" ], "sources_count": 8, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-calcium", "title": "Calcium (Ca) in cannabis: deficiency, transport, targets and sources", "category": "nutrients", "category_name": "Nutrients", "slug": "calcium", "url": "https://genetixbay.com/knowledge/nutrients/calcium.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/calcium.md", "summary": "Calcium builds cell walls and membranes and moves only in the transpiration stream, so it cannot be moved from old leaves to new ones. Feed about 150–200 mg/L Ca in soilless systems, and remember that most 'calcium deficiency' is a delivery problem (low transpiration, high humidity, root damage, competing K/Mg/NH4) rather than an empty bottle. Classic signs are distorted, stunted new growth and brown spots.", "tags": [ "calcium", "macronutrient", "deficiency", "immobile-nutrient", "transpiration", "coco", "ro-water", "cal-mag" ], "stage": [ "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Why do my new leaves have brown spots and twisted tips?", "Calcium deficiency or pH problem?", "How much calcium does cannabis need in coco or hydro?", "Why does calcium deficiency show up in coco with RO water?", "Can high humidity cause calcium deficiency?", "Do LED lights cause calcium deficiency?", "Why does only one strain in my room show calcium deficiency?" ], "myths": [], "related": [ "kb-nutrients-cal-mag", "kb-nutrients-magnesium", "kb-nutrients-potassium", "kb-nutrients-mobile-vs-immobile-nutrients", "kb-nutrients-nutrient-antagonism", "kb-ph-ec-buffering-coco" ], "sources_count": 8, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-chlorine", "title": "Chlorine and chloride (Cl) in cannabis: a micronutrient you never need to add", "category": "nutrients", "category_name": "Nutrients", "slug": "chlorine", "url": "https://genetixbay.com/knowledge/nutrients/chlorine.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/chlorine.md", "summary": "Chloride (Cl-) is an essential micronutrient for water splitting, osmotic balance and stomata, but the requirement is tiny and always met by water and fertiliser impurities. In practice chloride is a salinity problem, not a deficiency: keep it below roughly 50–70 mg/L in the feed, watch it in coco and some tap waters, and don't confuse chloride (a nutrient ion) with chlorine or chloramine (disinfectants).", "tags": [ "chloride", "chlorine", "micronutrient", "salinity", "toxicity", "water-quality", "coco" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Is chloride bad for cannabis?", "How much chloride is too much in irrigation water?", "Is calcium chloride safe to use in a cannabis feed?", "What's the difference between chlorine, chloride and chloramine?", "Can coco coir have high chloride?" ], "myths": [], "related": [ "kb-nutrients-sodium", "kb-ph-ec-water-quality", "kb-ph-ec-buffering-coco", "kb-nutrients-calcium", "kb-diagnosis-brown-burnt-tips" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-copper", "title": "Copper (Cu) in cannabis: limp, distorted new growth and root-burning excess", "category": "nutrients", "category_name": "Nutrients", "slug": "copper", "url": "https://genetixbay.com/knowledge/nutrients/copper.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/copper.md", "summary": "Copper is needed for photosynthetic electron transport, lignin and cell-wall strength. Cannabis copper deficiency showed late as stunted, distorted, slightly yellow new leaves that lost turgor and wilted, with a 45% biomass loss. Supply only about 0.03–0.1 mg/L Cu; excess (from copper fungicides, ionisers or pipework) damages roots first.", "tags": [ "copper", "micronutrient", "deficiency", "toxicity", "immobile-nutrient", "wilting", "hydro" ], "stage": [ "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "What does copper deficiency look like in cannabis?", "Why are my new leaves limp and curling down?", "How much copper in a hydro nutrient solution?", "Is copper toxic to cannabis roots?", "Can copper pipes or ionisers harm a hydro system?" ], "myths": [], "related": [ "kb-nutrients-zinc", "kb-nutrients-iron", "kb-nutrients-boron", "kb-nutrients-nutrient-antagonism", "kb-diagnosis-root-browning-hydro", "kb-diagnosis-yellow-new-growth" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-flushing", "title": "Flushing before harvest: myth (summary)", "category": "nutrients", "category_name": "Nutrients", "slug": "flushing", "url": "https://genetixbay.com/knowledge/nutrients/flushing.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/flushing.md", "summary": "Pre-harvest flushing is a myth that costs you yield and resin: it starves the plant while it packs on its final weight, trichomes and resin, and controlled studies found no gain in quality, minerals or cannabinoids. Cannabis stores what it takes up in its tissue, so plain water at the end doesn't wash it out. Feed through to harvest at stage-appropriate strength. The one valid flush treats the medium: a root-zone flush to clear salt build-up, at any stage. Full evidence in the flush debate article.", "tags": [ "flushing", "pre-harvest", "harvest", "ash", "taste", "myths", "nutrient-deprivation", "salt-buildup", "root-zone" ], "stage": [ "ripen", "harvest" ], "systems": [ "any" ], "evidence": "myth", "evidence_name": "Myth", "level": "beginner", "qa": [ "Should I flush my cannabis before harvest?", "Is flushing a myth?", "Does flushing improve taste or make white ash?", "When should I flush my medium?" ], "myths": [ "A pre-harvest flush 'cleans' the plant of nutrients" ], "related": [ "kb-harvest-cure-flush-debate", "kb-nutrients-feed-by-stage", "kb-ph-ec-runoff-testing", "kb-nutrients-organic-vs-mineral" ], "sources_count": 3, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-hydroponic-salts", "title": "Hydroponic salts explained: what each fertiliser salt supplies", "category": "nutrients", "category_name": "Nutrients", "slug": "hydroponic-salts", "url": "https://genetixbay.com/knowledge/nutrients/hydroponic-salts.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/hydroponic-salts.md", "summary": "Almost every mineral cannabis feed is built from about a dozen salts: calcium nitrate, potassium nitrate, monopotassium phosphate (MKP), magnesium sulfate, potassium sulfate, a few others, plus chelated iron and trace salts. Each one supplies known percentages of two elements, so 1 g/L of a salt gives (percent x 10) mg/L of each. Calcium must be kept apart from sulfate and phosphate in concentrated stocks, which is why feeds come as A and B.", "tags": [ "salts", "calcium-nitrate", "potassium-nitrate", "mkp", "epsom-salt", "potassium-sulfate", "chelates", "a-b-stock", "diy-nutrients" ], "stage": [ "any" ], "systems": [ "dwc", "rdwc", "nft", "ebb_flow", "drip", "coco", "rockwool", "aero" ], "evidence": "established", "evidence_name": "Established", "level": "intermediate", "qa": [ "What does calcium nitrate supply?", "How many ppm does 1 gram per litre of MKP give?", "Why are nutrients split into part A and part B?", "Which salts do I need to make my own hydro nutrients?", "What is the difference between EDTA and DTPA iron?", "Is Epsom salt the same as magnesium sulfate?" ], "myths": [], "related": [ "kb-nutrients-feed-by-stage", "kb-nutrients-iron", "kb-nutrients-cal-mag", "kb-nutrients-organic-vs-mineral", "kb-ph-ec-ec-ppm-scales", "kb-ph-ec-water-quality" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-iron", "title": "Iron (Fe) in cannabis: yellow new growth, chelates and pH", "category": "nutrients", "category_name": "Nutrients", "slug": "iron", "url": "https://genetixbay.com/knowledge/nutrients/iron.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/iron.md", "summary": "Iron is needed to make chlorophyll and run electron transport. Deficiency shows as interveinal yellowing of the newest leaves and is almost always caused by high root-zone pH or alkaline water, not a lack of iron in the feed. Supply about 1.5–3 mg/L Fe as a chelate matched to your pH: EDTA up to about 6.5, DTPA to about 7.5, EDDHA to about 9.", "tags": [ "iron", "micronutrient", "chelate", "edta", "dtpa", "eddha", "interveinal-chlorosis", "immobile-nutrient", "alkalinity" ], "stage": [ "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Why are my new leaves yellow with green veins?", "Which iron chelate is best for hydro: EDTA, DTPA or EDDHA?", "How many ppm iron in a nutrient solution?", "Iron deficiency or high pH?", "Can low pH cause iron toxicity?" ], "myths": [], "related": [ "kb-nutrients-manganese", "kb-nutrients-zinc", "kb-nutrients-hydroponic-salts", "kb-ph-ec-ph-nutrient-availability", "kb-ph-ec-water-quality", "kb-nutrients-nutrient-antagonism" ], "sources_count": 7, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-magnesium", "title": "Magnesium (Mg) in cannabis: interveinal yellowing, targets and the K-Ca competition", "category": "nutrients", "category_name": "Nutrients", "slug": "magnesium", "url": "https://genetixbay.com/knowledge/nutrients/magnesium.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/magnesium.md", "summary": "Magnesium sits at the centre of chlorophyll. Cannabis trials put the optimum at about 35–70 mg/L Mg in veg, and Mg supply raised cannabinoid and terpene production in flower. Deficiency shows as interveinal yellowing on older leaves with green veins; it is often induced by low pH or by too much potassium or calcium rather than an actual lack of Mg.", "tags": [ "magnesium", "macronutrient", "deficiency", "interveinal-chlorosis", "mobile-nutrient", "epsom-salt", "cal-mag" ], "stage": [ "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Why are my lower leaves yellow between the veins?", "How much magnesium does cannabis need?", "Can I use Epsom salt on cannabis? How much?", "Is it magnesium deficiency or too much potassium?", "Does magnesium increase THC or terpenes?", "Do LED lights need more magnesium?" ], "myths": [], "related": [ "kb-nutrients-cal-mag", "kb-nutrients-potassium", "kb-nutrients-calcium", "kb-nutrients-sulfur", "kb-nutrients-nutrient-antagonism", "kb-nutrients-mobile-vs-immobile-nutrients" ], "sources_count": 7, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-manganese", "title": "Manganese (Mn) in cannabis: netted chlorosis, low-pH toxicity and the iron balance", "category": "nutrients", "category_name": "Nutrients", "slug": "manganese", "url": "https://genetixbay.com/knowledge/nutrients/manganese.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/manganese.md", "summary": "Manganese is needed to split water in photosynthesis. Deficiency gives a bright yellow, netted interveinal chlorosis on upper and middle leaves with small tan spots; toxicity, usually from low root-zone pH, gives yellowing and necrosis of older leaf margins. Supply about 0.3–0.8 mg/L Mn and keep pH in range, because Mn availability swings strongly with pH.", "tags": [ "manganese", "micronutrient", "deficiency", "toxicity", "interveinal-chlorosis", "low-ph", "iron" ], "stage": [ "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "What does manganese deficiency look like in cannabis?", "Can low pH cause manganese toxicity?", "How much manganese in a hydroponic solution?", "Iron or manganese deficiency, how do I tell?", "Why do I have yellow netting between veins on top leaves?" ], "myths": [], "related": [ "kb-nutrients-iron", "kb-nutrients-zinc", "kb-nutrients-nutrient-antagonism", "kb-ph-ec-ph-nutrient-availability", "kb-diagnosis-yellow-new-growth" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-mobile-vs-immobile-nutrients", "title": "Mobile vs immobile nutrients: reading old vs new leaves", "category": "nutrients", "category_name": "Nutrients", "slug": "mobile-vs-immobile-nutrients", "url": "https://genetixbay.com/knowledge/nutrients/mobile-vs-immobile-nutrients.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/mobile-vs-immobile-nutrients.md", "summary": "Mobile nutrients (N, P, K, Mg, and also Cl, Mo, Ni) can be moved from old leaves to new ones through the phloem, so their shortages show on the oldest, lowest leaves first. Immobile nutrients (Ca, B, Fe, Mn, Cu, Zn, and partly S) stay where they were first deposited, so shortages show on new growth. It is the first fork in any deficiency diagnosis, with a few cannabis-specific exceptions.", "tags": [ "mobility", "phloem", "xylem", "diagnosis", "deficiency", "old-leaves", "new-leaves" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "beginner", "qa": [ "Which nutrients are mobile in cannabis?", "Why do deficiencies show on bottom leaves or top leaves?", "Yellow new growth vs yellow old leaves, what does it mean?", "Is calcium mobile or immobile?", "How do I tell nitrogen from iron deficiency?" ], "myths": [], "related": [ "kb-nutrients-nitrogen", "kb-nutrients-calcium", "kb-nutrients-iron", "kb-nutrients-sulfur", "kb-diagnosis-yellowing-lower-leaves", "kb-diagnosis-yellow-new-growth" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-molybdenum", "title": "Molybdenum (Mo) in cannabis: the trace element nitrate depends on", "category": "nutrients", "category_name": "Nutrients", "slug": "molybdenum", "url": "https://genetixbay.com/knowledge/nutrients/molybdenum.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/molybdenum.md", "summary": "Molybdenum is a cofactor for nitrate reductase, so a nitrate-fed plant cannot use its nitrogen without it. Cannabis needs a minuscule amount (about 0.01–0.05 mg/L Mo); in a 9-week trial, cannabis grown with no Mo showed no visible symptoms at all despite 96% lower leaf Mo. Unlike the other micronutrients, Mo becomes more available as pH rises, so deficiency is a low-pH, acid-soil problem.", "tags": [ "molybdenum", "micronutrient", "nitrate-reductase", "deficiency", "high-ph" ], "stage": [ "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "advanced", "qa": [ "Does cannabis need molybdenum?", "What does molybdenum deficiency look like?", "How much molybdenum in a hydroponic solution?", "Why would a plant fed nitrate still look nitrogen deficient?", "Is molybdenum available at low pH?" ], "myths": [], "related": [ "kb-nutrients-nitrogen", "kb-nutrients-hydroponic-salts", "kb-ph-ec-ph-nutrient-availability", "kb-nutrients-mobile-vs-immobile-nutrients" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-nickel", "title": "Nickel (Ni) in cannabis: essential, needed in traces, almost never worth adding", "category": "nutrients", "category_name": "Nutrients", "slug": "nickel", "url": "https://genetixbay.com/knowledge/nutrients/nickel.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/nickel.md", "summary": "Nickel became the most recently accepted essential plant micronutrient in 1987; its known job is activating urease, the enzyme that breaks down urea. Requirements are so small that contamination in salts, water and media normally covers them, and there is no published evidence of nickel deficiency in cannabis. Do not add nickel unless you feed urea in a very pure system; excess nickel is toxic and cannabis is known to accumulate metals.", "tags": [ "nickel", "micronutrient", "urease", "urea", "trace-element", "toxicity" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "advanced", "qa": [ "Does cannabis need nickel?", "Should I add nickel to my hydroponic nutrients?", "What does nickel do in plants?", "Can urea fertilizer cause leaf tip burn without nickel?", "Is nickel toxic to cannabis?" ], "myths": [], "related": [ "kb-nutrients-nitrogen", "kb-nutrients-hydroponic-salts", "kb-nutrients-molybdenum", "kb-ph-ec-water-quality" ], "sources_count": 3, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-nitrogen", "title": "Nitrogen (N) in cannabis: nitrate vs ammonium, deficiency, toxicity and targets", "category": "nutrients", "category_name": "Nutrients", "slug": "nitrogen", "url": "https://genetixbay.com/knowledge/nutrients/nitrogen.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/nitrogen.md", "summary": "Nitrogen drives leaf growth and photosynthesis. Cannabis does best on mostly nitrate N (about 150–200 mg/L in soilless veg and early flower), with ammonium kept at or below about 10–30% of total N; above 30% ammonium, cannabis trials show toxicity and lost yield. Deficiency yellows the oldest leaves first; excess gives dark, clawed leaves and soft, leafy growth.", "tags": [ "nitrogen", "nitrate", "ammonium", "macronutrient", "deficiency", "toxicity", "mobile-nutrient", "hydro", "coco", "soil" ], "stage": [ "seedling", "veg", "transition", "flower", "ripen" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "How much nitrogen does cannabis need in veg and flower?", "Nitrate or ammonium for cannabis?", "Why are my bottom leaves turning yellow?", "What does nitrogen toxicity look like? Dark green clawed leaves?", "How many ppm N in a hydro nutrient solution?", "Is ammonium bad for cannabis?", "Does lower nitrogen raise THC percentage?", "How do I taper nitrogen before harvest?" ], "myths": [], "related": [ "kb-harvest-cure-flush-debate", "kb-nutrients-mobile-vs-immobile-nutrients", "kb-nutrients-feed-by-stage", "kb-nutrients-hydroponic-salts", "kb-ph-ec-ph-drift-hydro", "kb-diagnosis-yellowing-lower-leaves" ], "sources_count": 8, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-nutrient-antagonism", "title": "Nutrient antagonism and Mulder's chart: what the evidence actually says", "category": "nutrients", "category_name": "Nutrients", "slug": "nutrient-antagonism", "url": "https://genetixbay.com/knowledge/nutrients/nutrient-antagonism.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/nutrient-antagonism.md", "summary": "Mulder's chart is a mid-20th-century wheel of nutrient interactions. It is a useful reminder that excess of one nutrient can suppress another, but it is a teaching sketch, not a quantitative tool. A review of 117 published interactions found synergy far more often than antagonism; the antagonisms that reliably matter in practice are among cations (K, Ca, Mg, NH4, Na), phosphorus with zinc and iron, and iron with manganese.", "tags": [ "antagonism", "synergism", "mulders-chart", "lockout", "potassium", "calcium", "magnesium", "phosphorus", "iron", "zinc" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "What is Mulder's chart?", "Does too much potassium lock out magnesium?", "What is nutrient lockout and is it real?", "Which nutrients compete with each other?", "Can too much phosphorus cause zinc deficiency?" ], "myths": [], "related": [ "kb-nutrients-potassium", "kb-nutrients-calcium", "kb-nutrients-magnesium", "kb-nutrients-phosphorus", "kb-nutrients-iron", "kb-nutrients-manganese" ], "sources_count": 7, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-organic-vs-mineral", "title": "Organic vs mineral nutrition for cannabis: what the trials show", "category": "nutrients", "category_name": "Nutrients", "slug": "organic-vs-mineral", "url": "https://genetixbay.com/knowledge/nutrients/organic-vs-mineral.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/organic-vs-mineral.md", "summary": "Plants absorb the same ions whether they came from a bag of salts or from compost; the differences are in speed, precision and what else comes along. Controlled cannabis trials show mineral feeds deliver nutrients more efficiently and organic liquid feeds need higher nominal N to match them. Organic and lower-input regimes can keep cannabinoid content per gram up while yield falls. Plants mostly don't care where the ions come from; slight differences in flavonoids or terpenes are possible but unproven, and no controlled blind trial shows organic flower tastes better.", "tags": [ "organic", "mineral", "synthetic", "living-soil", "fertiliser", "humic-acid", "flavour", "yield" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Is organic or synthetic nutrients better for cannabis?", "Does organic cannabis taste better?", "Can I use organic nutrients in hydroponics?", "Why do organic feeds need more nitrogen?", "Do humic acids help cannabis?" ], "myths": [], "related": [ "kb-nutrients-feed-by-stage", "kb-nutrients-hydroponic-salts", "kb-nutrients-nitrogen", "kb-harvest-cure-flush-debate", "kb-ph-ec-ph-nutrient-availability", "kb-diseases-root-rot-pythium" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-per-element-tricks", "title": "Per-element feeding tricks: what growers adjust, stage by stage", "category": "nutrients", "category_name": "Nutrients", "slug": "per-element-tricks", "url": "https://genetixbay.com/knowledge/nutrients/per-element-tricks.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/per-element-tricks.md", "summary": "Experienced growers change single elements by stage rather than just turning the whole feed up or down: tapering nitrogen in late flower, cutting the ammonium share after the flip, a little extra calcium through the stretch, small magnesium, boron and zinc bumps in flower, silicon in veg. Most of these tricks are grower practice with little or no controlled research behind them. Two popular ones are contradicted by research: extra phosphorus above about 30–60 mg/L and potassium 'ramps' above about 250 mg/L did not raise yield or cannabinoids in controlled cannabis trials. Sugars and molasses feed soil microbes only, not the plant, and do harm in hydro. The GenetixBay approach is to taper nitrogen and keep everything else fed, which needs single salts or per-element dosing.", "tags": [ "per-element-dosing", "nitrogen-taper", "ammonium", "phosphorus", "potassium", "calcium", "magnesium", "sulfur", "silicon", "micronutrients", "crop-steering", "ec", "additives", "single-salts" ], "stage": [ "veg", "transition", "flower", "ripen" ], "systems": [ "coco", "rockwool", "dwc", "rdwc", "nft", "ebb_flow", "drip", "aero" ], "evidence": "grower_practice", "evidence_name": "Grower practice", "level": "advanced", "qa": [ "What nutrient tricks do growers use in late flower?", "Should I raise potassium in late flower?", "Does more phosphorus in flower make bigger buds?", "How much ammonium should be in a flowering feed?", "Should I add extra calcium during the stretch?", "Does sulfur increase terpenes or skunky smell?", "Should I keep silica in flower?", "Does molasses make buds sweeter?", "Should I put plants in darkness before harvest?", "Do cold nights increase terpenes?", "Should I drop EC before harvest or just cut nitrogen?", "How do I taper nitrogen without dropping calcium?" ], "myths": [ "Molasses in the reservoir sweetens and fattens buds", "More sulfur means more terpenes" ], "related": [ "kb-nutrients-nitrogen", "kb-nutrients-feed-by-stage", "kb-nutrients-hydroponic-salts", "kb-nutrients-bloom-boosters", "kb-nutrients-nutrient-antagonism", "kb-nutrients-phosphorus" ], "sources_count": 10, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-phosphorus", "title": "Phosphorus (P) in cannabis: what it does, deficiency, excess and how much is enough", "category": "nutrients", "category_name": "Nutrients", "slug": "phosphorus", "url": "https://genetixbay.com/knowledge/nutrients/phosphorus.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/phosphorus.md", "summary": "Phosphorus powers energy transfer (ATP), roots and flowering, but cannabis needs far less than 'bloom' marketing implies. Controlled trials found no yield or cannabinoid gain above roughly 25–60 mg/L P in solution; extra P just ends up in the runoff and can tie up zinc, iron and calcium. Deficiency shows as dark, dull, olive-spotted older leaves and stunting.", "tags": [ "phosphorus", "macronutrient", "deficiency", "bloom", "mobile-nutrient", "hydro", "coco", "soil" ], "stage": [ "seedling", "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "How much phosphorus does cannabis need in flower?", "Does more phosphorus make bigger buds?", "What does phosphorus deficiency look like in cannabis?", "Why do my lower leaves have dark olive or brown spots?", "Can too much phosphorus cause zinc or iron deficiency?" ], "myths": [], "related": [ "kb-nutrients-bloom-boosters", "kb-nutrients-feed-by-stage", "kb-nutrients-nutrient-antagonism", "kb-nutrients-zinc", "kb-nutrients-iron", "kb-diagnosis-rust-spots" ], "sources_count": 7, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-potassium", "title": "Potassium (K) in cannabis: role, deficiency, excess and K-Ca-Mg balance", "category": "nutrients", "category_name": "Nutrients", "slug": "potassium", "url": "https://genetixbay.com/knowledge/nutrients/potassium.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/potassium.md", "summary": "Potassium runs water relations, stomata and sugar transport. Cannabis grows well on roughly 175–240 mg/L K in veg, and a flowering DWC trial found no yield response anywhere between 60 and 340 mg/L K, so more is not better. Deficiency scorches the margins and serrations of older leaves; excess K mainly does harm by suppressing calcium and magnesium uptake.", "tags": [ "potassium", "macronutrient", "deficiency", "antagonism", "calcium", "magnesium", "mobile-nutrient", "flower" ], "stage": [ "veg", "flower", "ripen" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "How much potassium does cannabis need in flower?", "Why are the edges of my lower leaves yellow and crispy?", "Can too much potassium cause magnesium or calcium deficiency?", "Do PK boosters help cannabis?", "What does potassium deficiency look like?" ], "myths": [], "related": [ "kb-nutrients-calcium", "kb-nutrients-magnesium", "kb-nutrients-nutrient-antagonism", "kb-nutrients-bloom-boosters", "kb-nutrients-feed-by-stage", "kb-diagnosis-yellowing-lower-leaves" ], "sources_count": 7, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-silicon", "title": "Silicon (Si) for cannabis: beneficial, not essential, and how to dose it", "category": "nutrients", "category_name": "Nutrients", "slug": "silicon", "url": "https://genetixbay.com/knowledge/nutrients/silicon.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/silicon.md", "summary": "Silicon is a beneficial element, not an essential one. It strengthens cell walls and reduces abiotic and some disease stress in many crops, and cannabis does take it up, but cannabis-specific evidence for yield or quality benefits is thin. If you use it, add potassium silicate first to the water at about 20–50 mg/L Si, before other nutrients, and correct pH afterwards because it is strongly alkaline.", "tags": [ "silicon", "silica", "potassium-silicate", "beneficial-element", "stress", "powdery-mildew", "hydro" ], "stage": [ "veg", "flower" ], "systems": [ "any" ], "evidence": "contested", "evidence_name": "Contested", "level": "intermediate", "qa": [ "Does cannabis need silica?", "How much silica to add to a hydro reservoir?", "Why do I add silica first when mixing nutrients?", "Does silicon prevent powdery mildew in cannabis?", "Silica ppm SiO2 vs Si, what's the difference?" ], "myths": [], "related": [ "kb-nutrients-hydroponic-salts", "kb-nutrients-potassium", "kb-ph-ec-ph-drift-hydro", "kb-diseases-powdery-mildew", "kb-nutrients-feed-by-stage" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-sodium", "title": "Sodium (Na) and cannabis: a salt to keep low, not a nutrient to add", "category": "nutrients", "category_name": "Nutrients", "slug": "sodium", "url": "https://genetixbay.com/knowledge/nutrients/sodium.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/sodium.md", "summary": "Sodium is not essential for cannabis. It can partly substitute for potassium in some plants, but in cannabis the controlled data show only harm: cannabinoids fall linearly as NaCl rises, and more than about 5 mM NaCl (115 mg/L Na) may reduce yield in hydro. Keep sodium below about 50 mg/L in the feed, never use ion-exchange softened water, and watch it build up in coco and recirculating systems.", "tags": [ "sodium", "salinity", "water-quality", "softened-water", "coco", "recirculating", "toxicity" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Is sodium bad for cannabis?", "Can I use softened water on cannabis?", "How much sodium is too much in irrigation water?", "Does salt stress increase THC?", "Why does sodium build up in recirculating hydro?" ], "myths": [], "related": [ "kb-nutrients-chlorine", "kb-nutrients-potassium", "kb-ph-ec-water-quality", "kb-ph-ec-buffering-coco", "kb-ph-ec-runoff-testing", "kb-diagnosis-brown-burnt-tips" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-sulfur", "title": "Sulfur (S) in cannabis: role, deficiency, targets and sulfate sources", "category": "nutrients", "category_name": "Nutrients", "slug": "sulfur", "url": "https://genetixbay.com/knowledge/nutrients/sulfur.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/sulfur.md", "summary": "Sulfur is part of the amino acids cysteine and methionine and of glutathione; cannabis also makes sulfur-containing aroma compounds. Feeds usually supply 50–120 mg/L S as sulfate without trying, via magnesium and potassium sulfate. Deficiency yellows the middle and newer leaves evenly, strongest at the leaflet base, and is rare unless a feed is built entirely from nitrates and chlorides.", "tags": [ "sulfur", "sulfate", "macronutrient", "deficiency", "intermediate-mobility", "aroma" ], "stage": [ "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "What does sulfur deficiency look like in cannabis?", "Why is the middle of my plant turning pale yellow?", "How much sulfur does cannabis need?", "Does sulfur make cannabis smell stronger?", "Sulfur deficiency or nitrogen deficiency?" ], "myths": [], "related": [ "kb-nutrients-nitrogen", "kb-nutrients-magnesium", "kb-nutrients-hydroponic-salts", "kb-nutrients-mobile-vs-immobile-nutrients", "kb-diagnosis-yellow-new-growth" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-nutrients-zinc", "title": "Zinc (Zn) in cannabis: small leaves, margin burn and the phosphorus link", "category": "nutrients", "category_name": "Nutrients", "slug": "zinc", "url": "https://genetixbay.com/knowledge/nutrients/zinc.html", "markdown_url": "https://genetixbay.com/knowledge/nutrients/zinc.md", "summary": "Zinc is needed for many enzymes and for making the growth hormone auxin. Deficiency in cannabis shows late, as yellowing and then tan necrosis along the toothed margins of new leaves, often with small leaves and short internodes elsewhere in the literature. Supply about 0.1–0.5 mg/L Zn; high pH and very high phosphorus are the usual reasons a fed plant runs short.", "tags": [ "zinc", "micronutrient", "deficiency", "toxicity", "immobile-nutrient", "phosphorus", "high-ph" ], "stage": [ "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "What does zinc deficiency look like in cannabis?", "Why are my new leaves small with burnt edges?", "How much zinc in a hydro feed?", "Can too much phosphorus cause zinc deficiency?", "Is zinc toxic to cannabis?" ], "myths": [], "related": [ "kb-nutrients-phosphorus", "kb-nutrients-iron", "kb-nutrients-copper", "kb-nutrients-nutrient-antagonism", "kb-ph-ec-ph-nutrient-availability", "kb-diagnosis-yellow-new-growth" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-ph-ec-buffering-coco", "title": "Buffering coco coir: why it matters and how to do it", "category": "ph-ec", "category_name": "pH and EC", "slug": "buffering-coco", "url": "https://genetixbay.com/knowledge/ph-ec/buffering-coco.html", "markdown_url": "https://genetixbay.com/knowledge/ph-ec/buffering-coco.md", "summary": "Coco coir has a high cation exchange capacity that arrives loaded with potassium and sodium. Unbuffered, it grabs calcium and magnesium from your feed and releases K and Na, causing early Ca/Mg deficiency. Buffering means soaking washed coco in a calcium (and usually magnesium) nitrate solution so the exchange sites are filled with Ca and Mg before planting, then rinsing. It is standard grower and industry practice with sound chemistry behind it, though controlled studies on cannabis are lacking.", "tags": [ "coco", "coir", "buffering", "cation-exchange", "calcium-nitrate", "potassium", "sodium", "cal-mag" ], "stage": [ "seedling", "veg" ], "systems": [ "coco" ], "evidence": "grower_practice", "evidence_name": "Grower practice", "level": "intermediate", "qa": [ "Do I need to buffer coco coir?", "How do I buffer coco with Cal-Mag or calcium nitrate?", "Why does my plant get calcium deficiency in new coco?", "What is the difference between washed and buffered coco?", "How long should I soak coco to buffer it?", "Can I reuse coco without buffering?" ], "myths": [], "related": [ "kb-nutrients-cal-mag", "kb-nutrients-calcium", "kb-nutrients-magnesium", "kb-nutrients-sodium", "kb-nutrients-chlorine", "kb-ph-ec-runoff-testing" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-ph-ec-ec-ppm-scales", "title": "EC vs PPM: the 500 and 700 scales, CF, and how to convert", "category": "ph-ec", "category_name": "pH and EC", "slug": "ec-ppm-scales", "url": "https://genetixbay.com/knowledge/ph-ec/ec-ppm-scales.html", "markdown_url": "https://genetixbay.com/knowledge/ph-ec/ec-ppm-scales.md", "summary": "EC (electrical conductivity, in mS/cm) is what every meter actually measures. 'PPM' or TDS readings are EC multiplied by an assumed factor: 0.5 on the 500 (NaCl) scale, 0.7 on the 700 (442 or KCl-style) scale, sometimes 0.64. So 1.0 mS/cm reads 500 ppm on one meter and 700 ppm on another. Always talk in EC, or state the scale. Feed charts quoting ppm without a scale are ambiguous by 40%.", "tags": [ "ec", "ppm", "tds", "conversion", "500-scale", "700-scale", "cf", "meters", "units" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "beginner", "qa": [ "How do I convert EC to ppm?", "What is the difference between the 500 and 700 ppm scales?", "Is my meter 500 or 700 scale?", "What is CF in hydroponics?", "What EC is 1000 ppm?", "mS/cm vs µS/cm vs dS/m?" ], "myths": [], "related": [ "kb-nutrients-feed-by-stage", "kb-ph-ec-meter-calibration", "kb-ph-ec-runoff-testing", "kb-ph-ec-water-quality" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-ph-ec-meter-calibration", "title": "pH and EC meter calibration: buffers, slope, storage and when to replace a probe", "category": "ph-ec", "category_name": "pH and EC", "slug": "meter-calibration", "url": "https://genetixbay.com/knowledge/ph-ec/meter-calibration.html", "markdown_url": "https://genetixbay.com/knowledge/ph-ec/meter-calibration.md", "summary": "Calibrate pH meters with at least two fresh buffers that bracket your readings (pH 7 then pH 4 for growing), before any session where decisions matter and at least weekly. Store glass pH probes wet in storage solution or pH 4/7 buffer, never in RO water or dry. Check EC meters against a 1.413 mS/cm standard. A pH probe with a slope below about 90-95% or one that can no longer be adjusted to buffer should be replaced; typical glass electrodes last one to two years.", "tags": [ "calibration", "ph-meter", "ec-meter", "probe", "buffer", "slope", "offset", "storage-solution", "sensors", "maintenance" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "beginner", "qa": [ "How do I calibrate a pH pen?", "How often should I calibrate my pH meter?", "How should I store a pH probe?", "Why does my pH meter drift?", "What is pH probe slope and offset?", "How do I calibrate an EC meter?", "When should I replace my pH probe?" ], "myths": [], "related": [ "kb-ph-ec-ph-nutrient-availability", "kb-ph-ec-ec-ppm-scales", "kb-ph-ec-runoff-testing", "kb-ph-ec-ph-drift-hydro" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-ph-ec-ph-nutrient-availability", "title": "pH and nutrient availability: what pH really controls, by medium", "category": "ph-ec", "category_name": "pH and EC", "slug": "ph-nutrient-availability", "url": "https://genetixbay.com/knowledge/ph-ec/ph-nutrient-availability.html", "markdown_url": "https://genetixbay.com/knowledge/ph-ec/ph-nutrient-availability.md", "summary": "pH controls how soluble each nutrient is and how well roots absorb it. The accepted ranges are soil about 6.0–7.0 and soilless/hydro about 5.5–6.5 (sweet spots: 5.5–6.2 in hydro, 5.8–6.3 in coco and rockwool, 6.2–6.8 in soil), and drift within the range is normal. High pH starves plants of iron, manganese, zinc, boron and phosphorus; low pH makes iron and manganese overly available and reduces calcium, magnesium and molybdenum. The classic availability bar chart was built for mineral soils and overstates the effect in chelated soilless feeds. The ranges are broadly agreed accepted practice, from extension and grower consensus.", "tags": [ "ph", "nutrient-availability", "lockout", "hydro", "coco", "soil", "chelates", "micronutrients" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "beginner", "qa": [ "What pH should I use for cannabis in soil, coco and hydro?", "What is nutrient lockout from pH?", "Why is the hydro pH range lower than soil?", "Is the pH nutrient availability chart accurate?", "What happens if my pH is too high?", "What happens if my pH is too low?", "Is it OK if my pH drifts?" ], "myths": [], "related": [ "kb-harvest-cure-flush-debate", "kb-ph-ec-ph-drift-hydro", "kb-ph-ec-water-quality", "kb-ph-ec-meter-calibration", "kb-ph-ec-runoff-testing", "kb-nutrients-iron" ], "sources_count": 7, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-ph-ec-ph-drift-hydro", "title": "pH drift in hydro: why reservoir pH rises (and sometimes falls)", "category": "ph-ec", "category_name": "pH and EC", "slug": "ph-drift-hydro", "url": "https://genetixbay.com/knowledge/ph-ec/ph-drift-hydro.html", "markdown_url": "https://genetixbay.com/knowledge/ph-ec/ph-drift-hydro.md", "summary": "Reservoir pH usually rises because plants absorb nitrate and release hydroxide or bicarbonate to stay electrically balanced; aeration driving off CO2, alkaline top-up water and algae add to it. Ammonium does the opposite. A steady upward drift of a few tenths per day in a healthy, growing system is normal. Manage it with a small ammonium share (5–15% of N), acidifying alkaline water, and letting pH ride within 5.5–6.2 rather than chasing a single number. A fast unexplained fall, or a rise with brown roots, points to root or microbial trouble.", "tags": [ "ph-drift", "hydro", "dwc", "rdwc", "nft", "nitrate", "ammonium", "alkalinity", "co2", "reservoir" ], "stage": [ "any" ], "systems": [ "dwc", "rdwc", "nft", "ebb_flow", "aero", "drip" ], "evidence": "established", "evidence_name": "Established", "level": "intermediate", "qa": [ "Why does my hydro pH keep going up?", "Why is my DWC pH dropping?", "How often should I adjust pH in hydro?", "Is pH drift a sign of a problem?", "How do I stop pH swings in RO water?", "Does an air stone raise pH?" ], "myths": [], "related": [ "kb-ph-ec-ph-nutrient-availability", "kb-ph-ec-water-quality", "kb-ph-ec-meter-calibration", "kb-nutrients-nitrogen", "kb-nutrients-silicon", "kb-diagnosis-root-browning-hydro" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-ph-ec-runoff-testing", "title": "Runoff testing: how to measure root-zone pH and EC and what the numbers mean", "category": "ph-ec", "category_name": "pH and EC", "slug": "runoff-testing", "url": "https://genetixbay.com/knowledge/ph-ec/runoff-testing.html", "markdown_url": "https://genetixbay.com/knowledge/ph-ec/runoff-testing.md", "summary": "Runoff (leachate) pH and EC tell you what the roots are actually sitting in, which is often different from what you fed. Use the pour-through method: water to full saturation, wait 30 minutes to 2 hours, then pour a measured amount of water on top and collect about 50 mL. Compare runoff EC with input EC: higher means salts are building up, much lower means the plant is hungry or you are over-leaching. Track the trend over weeks rather than reacting to one reading.", "tags": [ "runoff", "pour-through", "leachate", "ec", "ph", "coco", "soil", "rockwool", "salt-buildup", "monitoring" ], "stage": [ "any" ], "systems": [ "soil", "coco", "rockwool", "drip", "living_soil" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "How do I test runoff pH and EC?", "What should my runoff EC be compared to my input?", "Why is my runoff EC higher than what I feed?", "Why is my runoff pH different from my feed pH?", "What is the pour-through method?", "How much runoff should I get in coco?", "How do I flush salt build-up out of my medium?", "Should I flush before harvest?" ], "myths": [], "related": [ "kb-harvest-cure-flush-debate", "kb-ph-ec-ph-nutrient-availability", "kb-ph-ec-ec-ppm-scales", "kb-ph-ec-meter-calibration", "kb-ph-ec-buffering-coco", "kb-nutrients-flushing" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-ph-ec-water-quality", "title": "Water quality for cannabis: RO vs tap, alkalinity, bicarbonates and chloramine", "category": "ph-ec", "category_name": "pH and EC", "slug": "water-quality", "url": "https://genetixbay.com/knowledge/ph-ec/water-quality.html", "markdown_url": "https://genetixbay.com/knowledge/ph-ec/water-quality.md", "summary": "Get a water report before choosing a feed. Alkalinity (bicarbonate), not water pH, is what pushes root-zone pH up over time; above about 100–150 mg/L as CaCO3 (2–3 meq/L) it should be partly neutralised with acid. Tap water may also add useful Ca and Mg, or harmful sodium, chloride and boron. RO water removes nearly everything, which gives precise control but means you must add back Ca and Mg. Chloramine does not evaporate; remove it with long-contact or catalytic carbon or ascorbic acid if you run living soil or beneficial microbes.", "tags": [ "water-quality", "ro", "reverse-osmosis", "tap-water", "alkalinity", "bicarbonate", "hardness", "chloramine", "chlorine", "sodium", "acid-injection" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Should I use RO water or tap water for cannabis?", "What is alkalinity and why does it matter?", "How much acid do I need to treat hard water?", "Does chloramine hurt cannabis or soil microbes?", "Does letting tap water sit remove chloramine?", "What is a good EC for source water?" ], "myths": [], "related": [ "kb-ph-ec-ph-nutrient-availability", "kb-ph-ec-ph-drift-hydro", "kb-nutrients-cal-mag", "kb-nutrients-sodium", "kb-nutrients-chlorine", "kb-nutrients-boron" ], "sources_count": 7, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-systems-bottom-watering-wick", "title": "Bottom-watering, soak trays and wick (self-watering) systems", "category": "systems", "category_name": "Systems", "slug": "bottom-watering-wick", "url": "https://genetixbay.com/knowledge/systems/bottom-watering-wick.html", "markdown_url": "https://genetixbay.com/knowledge/systems/bottom-watering-wick.md", "summary": "Bottom-watering lets pots draw solution up from a tray, either by a timed soak (flood 2–5 cm for 10–30 minutes, then drain) or by a constant shallow level held by a float valve or wick. It is gentle and labour-saving and suits soil, but salts accumulate at the top of the pot, so feed at lower EC than top-feeding and top-water to runoff every week or two.", "tags": [ "bottom-watering", "subirrigation", "wick", "self-watering", "float-valve", "soak" ], "stage": [ "any" ], "systems": [ "soil", "coco", "living_soil" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Is bottom watering good for cannabis?", "Do self-watering pots work for cannabis?", "Why is there white crust on top of my bottom-watered pots?", "Should I bottom water seedlings?" ], "myths": [], "related": [ "kb-systems-ebb-and-flow", "kb-systems-soil", "kb-systems-living-soil", "kb-systems-choosing-a-system" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-systems-choosing-a-system", "title": "Choosing your growing system: soil, coco, rockwool or hydro", "category": "systems", "category_name": "Systems", "slug": "choosing-a-system", "url": "https://genetixbay.com/knowledge/systems/choosing-a-system.html", "markdown_url": "https://genetixbay.com/knowledge/systems/choosing-a-system.md", "summary": "Choose by how much attention and measurement you can give, not by yield claims. Soil and living soil forgive mistakes for days; coco and drip need daily feeding; DWC, NFT and aeroponics grow fast but can lose roots within hours if a pump or air supply fails. No controlled study shows one system out-yielding the others when light and climate are equal.", "tags": [ "comparison", "beginner", "soil", "coco", "hydroponics", "aeroponics", "decision" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "grower_practice", "evidence_name": "Grower practice", "level": "beginner", "qa": [ "What is the best growing system for a beginner?", "Is hydro better than soil for cannabis?", "Which system gives the biggest yield?", "Coco or soil?", "Which hydroponic system is easiest?" ], "myths": [], "related": [ "kb-systems-soil", "kb-systems-living-soil", "kb-systems-coco", "kb-systems-rockwool", "kb-systems-dwc", "kb-systems-rdwc" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-systems-dwc", "title": "Deep water culture (DWC)", "category": "systems", "category_name": "Systems", "slug": "dwc", "url": "https://genetixbay.com/knowledge/systems/dwc.html", "markdown_url": "https://genetixbay.com/knowledge/systems/dwc.md", "summary": "In DWC roots hang in an aerated nutrient solution. It grows fast but depends on two things: dissolved oxygen (keep above about 6 mg/L, ideally near saturation) and solution temperature (18–22 °C / 64–72 °F). Warm, poorly aerated water is how Pythium root rot starts. Run pH 5.6–6.0 and EC 0.8–2.0 mS/cm by stage, and treat the air pump as life support.", "tags": [ "dwc", "hydroponics", "dissolved-oxygen", "reservoir", "air-pump", "root-rot" ], "stage": [ "veg", "flower" ], "systems": [ "dwc" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Should my reservoir be sterile or full of beneficial microbes?", "What water temperature for DWC?", "How much air does a DWC bucket need?", "Why are my DWC roots brown and slimy?", "How often should I change the DWC reservoir?", "What pH for DWC cannabis?" ], "myths": [], "related": [ "kb-systems-rdwc", "kb-systems-kratky", "kb-systems-nft", "kb-systems-choosing-a-system", "kb-environment-temperature-by-stage", "kb-diseases-root-rot-pythium" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-systems-drain-to-waste-crop-steering", "title": "Drain-to-waste drip and crop steering (generative vs vegetative dryback)", "category": "systems", "category_name": "Systems", "slug": "drain-to-waste-crop-steering", "url": "https://genetixbay.com/knowledge/systems/drain-to-waste-crop-steering.html", "markdown_url": "https://genetixbay.com/knowledge/systems/drain-to-waste-crop-steering.md", "summary": "Drain-to-waste drip sends fresh solution every shot and discards runoff, so you control the root zone by irrigation timing, shot size and substrate EC measured with a VWC/EC probe. Vegetative steering uses earlier first shots, larger shots and small overnight drybacks (about 10–15 % VWC); generative steering delays the first shot, uses smaller shots, longer P3 and larger drybacks (about 20–35 %) with higher substrate EC. The ranges are grower practice; one cannabis study found controlled late-flower drought raised cannabinoid concentration.", "tags": [ "drain-to-waste", "crop-steering", "dryback", "vwc", "substrate-ec", "p1-p2-p3", "generative", "vegetative" ], "stage": [ "veg", "transition", "flower" ], "systems": [ "drip", "coco", "rockwool" ], "evidence": "grower_practice", "evidence_name": "Grower practice", "level": "advanced", "qa": [ "What is crop steering?", "What is generative vs vegetative steering?", "What are P1, P2 and P3 irrigation phases?", "How much dryback should I run in flower?", "Do I need a substrate sensor for crop steering?", "Does drought stress increase THC?" ], "myths": [], "related": [ "kb-systems-rockwool", "kb-systems-coco", "kb-systems-recirculating-drip", "kb-systems-choosing-a-system", "kb-harvest-cure-flush-debate" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-systems-ebb-and-flow", "title": "Ebb and flow (flood and drain)", "category": "systems", "category_name": "Systems", "slug": "ebb-and-flow", "url": "https://genetixbay.com/knowledge/systems/ebb-and-flow.html", "markdown_url": "https://genetixbay.com/knowledge/systems/ebb-and-flow.md", "summary": "A pump floods a table or tray of pots to a standpipe height, then the solution drains back to the reservoir. Each flood refreshes water and pulls fresh air into the medium as it drains. Typical schedules: clay pebbles 3–6 floods per light period of 10–15 minutes, coco or rockwool 1–3. It is robust because the media buffer pump failures for days, but salts can build up at the top of the medium.", "tags": [ "ebb-and-flow", "flood-and-drain", "flood-table", "clay-pebbles", "recirculating" ], "stage": [ "veg", "flower" ], "systems": [ "ebb_flow" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "How often should I flood an ebb and flow table?", "What media works in ebb and flow?", "How long should each flood last?", "Why are salts building up on top of my pots?" ], "myths": [], "related": [ "kb-systems-bottom-watering-wick", "kb-systems-recirculating-drip", "kb-systems-rockwool", "kb-systems-coco", "kb-systems-choosing-a-system" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-systems-fogponics", "title": "Fogponics: ultrasonic fog for roots (a supplement, not a system)", "category": "systems", "category_name": "Systems", "slug": "fogponics", "url": "https://genetixbay.com/knowledge/systems/fogponics.html", "markdown_url": "https://genetixbay.com/knowledge/systems/fogponics.md", "summary": "Fogponics uses ultrasonic transducers to make a 5–10 µm water fog that is blown into a root chamber. Fog carries very little dissolved nutrient (salts stay behind and concentrate in the fogger tank), transducers wear out in roughly 1,000–3,000 hours and run hot, so GenetixBay treats fog as a humidity supplement for cloning domes and aeroponic chambers, not as a standalone way to feed a flowering plant.", "tags": [ "fogponics", "ultrasonic", "fogger", "cloning", "root-chamber" ], "stage": [ "seedling", "veg" ], "systems": [ "aero" ], "evidence": "grower_practice", "evidence_name": "Grower practice", "level": "intermediate", "qa": [ "Does fogponics work for cannabis?", "Can foggers feed plants nutrients?", "How long do ultrasonic foggers last?", "Is fogponics good for clones?" ], "myths": [], "related": [ "kb-systems-lpa-aeroponics", "kb-systems-hpa-aeroponics", "kb-germination-seedling-care" ], "sources_count": 2, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-systems-coco", "title": "Growing in coco coir", "category": "systems", "category_name": "Systems", "slug": "coco", "url": "https://genetixbay.com/knowledge/systems/coco.html", "markdown_url": "https://genetixbay.com/knowledge/systems/coco.md", "summary": "Coco coir is a hydroponic substrate that looks like soil: inert-ish, airy, and fed every irrigation with a complete mineral solution at pH 5.8–6.2 and EC 1.2–2.4 mS/cm with 10–20 % runoff. Use pre-washed, buffered coco or buffer it yourself with a calcium/magnesium solution, because raw coir holds potassium and sodium and grabs calcium and magnesium.", "tags": [ "coco", "coir", "buffering", "cal-mag", "runoff", "high-frequency-fertigation" ], "stage": [ "any" ], "systems": [ "coco" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "What size pot for coco?", "Do I need to buffer coco coir?", "What pH for coco?", "How often should I water coco?", "Why do my coco plants get calcium deficiency?", "Can coco dry out completely?", "Coco vs soil for beginners?" ], "myths": [], "related": [ "kb-harvest-cure-flush-debate", "kb-systems-recirculating-drip", "kb-systems-drain-to-waste-crop-steering", "kb-systems-soil", "kb-systems-rockwool", "kb-systems-choosing-a-system" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-systems-rockwool", "title": "Growing in rockwool (stonewool cubes and slabs)", "category": "systems", "category_name": "Systems", "slug": "rockwool", "url": "https://genetixbay.com/knowledge/systems/rockwool.html", "markdown_url": "https://genetixbay.com/knowledge/systems/rockwool.md", "summary": "Rockwool is an inert, unbuffered mineral fibre that holds a lot of water and air and gives precise control over the root zone. Pre-soak at pH about 5.5, run pH 5.5–6.0 and EC 1.8–3.0 mS/cm in flower, and manage it by volumetric water content and slab EC. It is the native medium of crop steering, and it punishes neglect quickly because nothing buffers mistakes.", "tags": [ "rockwool", "stonewool", "slab", "cube", "crop-steering", "inert-media" ], "stage": [ "any" ], "systems": [ "rockwool" ], "evidence": "supported", "evidence_name": "Supported", "level": "advanced", "qa": [ "Do I need to pre-soak rockwool?", "What pH for rockwool?", "How do I know when to water rockwool slabs?", "Rockwool vs coco for cannabis?", "Is rockwool dust dangerous?" ], "myths": [], "related": [ "kb-harvest-cure-flush-debate", "kb-systems-drain-to-waste-crop-steering", "kb-systems-coco", "kb-systems-ebb-and-flow", "kb-systems-recirculating-drip", "kb-systems-choosing-a-system" ], "sources_count": 3, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-systems-soil", "title": "Growing in soil (potting mix with bottled feed)", "category": "systems", "category_name": "Systems", "slug": "soil", "url": "https://genetixbay.com/knowledge/systems/soil.html", "markdown_url": "https://genetixbay.com/knowledge/systems/soil.md", "summary": "Soil (a peat- or compost-based potting mix fed with dilute bottled nutrients) is the most forgiving system: it buffers pH and nutrients and holds water for days. Water to light runoff when the pot is light, feed at EC 0.8–1.6 mS/cm with water at pH 6.2–6.8, and remember that over-watering, not under-feeding, kills most soil plants.", "tags": [ "soil", "potting-mix", "watering", "ph", "beginner", "containers" ], "stage": [ "any" ], "systems": [ "soil" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Does a bigger pot give a bigger yield?", "What pH should I water my soil plants at?", "How often should I water cannabis in soil?", "Can I use hydro nutrients in soil?", "What size pot do I need?", "Why are my soil plants drooping when the soil is wet?" ], "myths": [], "related": [ "kb-harvest-cure-flush-debate", "kb-systems-living-soil", "kb-systems-coco", "kb-systems-bottom-watering-wick", "kb-systems-choosing-a-system", "kb-germination-transplanting" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-systems-hpa-aeroponics", "title": "High-pressure aeroponics (HPA)", "category": "systems", "category_name": "Systems", "slug": "hpa-aeroponics", "url": "https://genetixbay.com/knowledge/systems/hpa-aeroponics.html", "markdown_url": "https://genetixbay.com/knowledge/systems/hpa-aeroponics.md", "summary": "HPA atomises nutrient solution at roughly 80–100 psi (5.5–7 bar) through fine nozzles into a root chamber, giving fine droplets (about 10–100 µm) and very high root oxygen. It can grow outstanding root systems but has the shortest failure margin of any system: roots can be damaged within tens of minutes if misting stops. It needs an accumulator, pressure monitoring, filtration, anti-drip nozzles and a backup plan.", "tags": [ "aeroponics", "hpa", "misting", "accumulator", "solenoid", "nozzles" ], "stage": [ "veg", "flower" ], "systems": [ "aero" ], "evidence": "supported", "evidence_name": "Supported", "level": "advanced", "qa": [ "What pressure for high-pressure aeroponics?", "What mist cycle for HPA cannabis?", "Is HPA worth it over LPA or DWC?", "What happens if my HPA pump fails?" ], "myths": [], "related": [ "kb-systems-lpa-aeroponics", "kb-systems-fogponics", "kb-systems-choosing-a-system" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-systems-kratky", "title": "Kratky (passive, non-circulating hydroponics)", "category": "systems", "category_name": "Systems", "slug": "kratky", "url": "https://genetixbay.com/knowledge/systems/kratky.html", "markdown_url": "https://genetixbay.com/knowledge/systems/kratky.md", "summary": "Kratky is hydroponics with no pump: the plant sits above a container of nutrient solution, drinks it down, and the growing air gap gives the upper roots oxygen. It was developed and published for lettuce and tomatoes at the University of Hawaii. Cannabis can be grown this way, but its large water use means big containers, careful refills that keep the air gap, and close attention to water temperature and EC drift.", "tags": [ "kratky", "passive-hydroponics", "non-circulating", "beginner", "no-pump" ], "stage": [ "seedling", "veg", "flower" ], "systems": [ "dwc" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Can you grow cannabis with the Kratky method?", "How big a Kratky container for cannabis?", "Should I refill a Kratky reservoir to the top?", "Why are my Kratky roots rotting?" ], "myths": [], "related": [ "kb-systems-dwc", "kb-systems-choosing-a-system", "kb-environment-temperature-by-stage" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-systems-living-soil", "title": "Living soil (no-till, water-only organic growing)", "category": "systems", "category_name": "Systems", "slug": "living-soil", "url": "https://genetixbay.com/knowledge/systems/living-soil.html", "markdown_url": "https://genetixbay.com/knowledge/systems/living-soil.md", "summary": "Living soil is a large, biologically active, amended organic soil that is reused without tilling and watered with plain dechlorinated water; soil organisms release nutrients. It is forgiving and low-input once established but slow to correct, so build it well, keep it moist and mulched, never use salt-based nutrients or sanitisers on it, and don't chase pH. Most of its claims are grower practice rather than tested in cannabis.", "tags": [ "living-soil", "no-till", "organic", "microbes", "compost", "mulch", "cover-crop" ], "stage": [ "any" ], "systems": [ "living_soil" ], "evidence": "grower_practice", "evidence_name": "Grower practice", "level": "intermediate", "qa": [ "What is living soil and how is it different from regular soil?", "Do I need to pH water for living soil?", "How big a container for living soil?", "Can I use bottled nutrients in living soil?", "How do I fix a deficiency in living soil?" ], "myths": [], "related": [ "kb-harvest-cure-flush-debate", "kb-systems-soil", "kb-systems-bottom-watering-wick", "kb-systems-choosing-a-system", "kb-nutrients-organic-vs-mineral" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-systems-lpa-aeroponics", "title": "Low-pressure aeroponics (LPA)", "category": "systems", "category_name": "Systems", "slug": "lpa-aeroponics", "url": "https://genetixbay.com/knowledge/systems/lpa-aeroponics.html", "markdown_url": "https://genetixbay.com/knowledge/systems/lpa-aeroponics.md", "summary": "LPA uses an ordinary submersible pump and spray heads to drench roots hanging in a dark chamber with coarse droplets. It is essentially a spray-assisted hydro system: forgiving (a pool on the chamber floor keeps roots wet for hours), cheap, and easier than true high-pressure aeroponics. Run sprays continuously or on short cycles such as 1 minute on, 4 off, with a chamber humidity watchdog and solution at 18–22 °C.", "tags": [ "aeroponics", "lpa", "sprayers", "root-chamber", "hydroponics" ], "stage": [ "veg", "flower" ], "systems": [ "aero" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "What is low-pressure aeroponics?", "LPA vs HPA: which is better?", "What spray cycle for low-pressure aeroponics?", "Why do my aeroponic sprayers keep clogging?" ], "myths": [], "related": [ "kb-systems-hpa-aeroponics", "kb-systems-fogponics", "kb-systems-nft", "kb-systems-dwc", "kb-systems-choosing-a-system" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-systems-nft", "title": "Nutrient film technique (NFT)", "category": "systems", "category_name": "Systems", "slug": "nft", "url": "https://genetixbay.com/knowledge/systems/nft.html", "markdown_url": "https://genetixbay.com/knowledge/systems/nft.md", "summary": "In NFT a thin, continuous film of nutrient solution runs down sloped channels past bare roots. It is efficient and well proven for lettuce and herbs, but large cannabis root masses can dam the channel, and roots dry within one to three hours if the pump stops. Keep flow continuous (about 1–2 L/min per channel), slope about 1:30 to 1:100, and solution at 18–22 °C.", "tags": [ "nft", "hydroponics", "channels", "gullies", "recirculating", "root-mat" ], "stage": [ "veg", "flower" ], "systems": [ "nft" ], "evidence": "supported", "evidence_name": "Supported", "level": "advanced", "qa": [ "Does NFT work for cannabis?", "What flow rate for an NFT channel?", "What slope should NFT gullies have?", "What happens if my NFT pump stops?" ], "myths": [], "related": [ "kb-systems-dwc", "kb-systems-rdwc", "kb-systems-lpa-aeroponics", "kb-systems-choosing-a-system" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-systems-rdwc", "title": "Recirculating deep water culture (RDWC)", "category": "systems", "category_name": "Systems", "slug": "rdwc", "url": "https://genetixbay.com/knowledge/systems/rdwc.html", "markdown_url": "https://genetixbay.com/knowledge/systems/rdwc.md", "summary": "RDWC links several DWC sites to a control bucket and circulates the solution with a pump, so one reservoir sets pH, EC and temperature for every plant and a single chiller cools the lot. It adds circulation and plumbing failure modes to DWC's oxygen and temperature risks. Targets match DWC: 18–22 °C, DO above 6 mg/L, pH 5.6–6.0.", "tags": [ "rdwc", "hydroponics", "recirculating", "control-bucket", "chiller", "dissolved-oxygen" ], "stage": [ "veg", "flower" ], "systems": [ "rdwc" ], "evidence": "grower_practice", "evidence_name": "Grower practice", "level": "advanced", "qa": [ "Should my reservoir be sterile or full of beneficial microbes?", "What is the difference between DWC and RDWC?", "How big should the RDWC control bucket be?", "How fast should the RDWC pump circulate?", "One plant in my RDWC has root rot; what now?" ], "myths": [], "related": [ "kb-systems-dwc", "kb-systems-nft", "kb-systems-choosing-a-system", "kb-environment-temperature-by-stage", "kb-diseases-root-rot-pythium" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-systems-recirculating-drip", "title": "Recirculating drip (top-feed, runoff returns)", "category": "systems", "category_name": "Systems", "slug": "recirculating-drip", "url": "https://genetixbay.com/knowledge/systems/recirculating-drip.html", "markdown_url": "https://genetixbay.com/knowledge/systems/recirculating-drip.md", "summary": "A pump pushes nutrient solution through drip emitters into pots of coco, rockwool or clay pebbles and the runoff returns to the reservoir. It saves water and nutrients but the reservoir slowly drifts as runoff brings back salts and root exudates, so monitor runoff and refresh when reservoir chemistry diverges. Typical shots are 2–6 % of pot volume, first shot 1–2 h after lights-on, none in the dark.", "tags": [ "drip", "top-feed", "recirculating", "emitters", "coco", "clay-pebbles", "runoff" ], "stage": [ "veg", "flower" ], "systems": [ "drip" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "How many drip emitters per plant?", "Should I recirculate drip runoff?", "How often should I change a recirculating reservoir?", "What shot size for drip irrigation in coco?" ], "myths": [], "related": [ "kb-harvest-cure-flush-debate", "kb-systems-drain-to-waste-crop-steering", "kb-systems-coco", "kb-systems-rockwool", "kb-systems-ebb-and-flow", "kb-systems-choosing-a-system" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-training-defoliation-lollipopping", "title": "Defoliation and lollipopping: what to remove, when, and the evidence", "category": "training", "category_name": "Training", "slug": "defoliation-lollipopping", "url": "https://genetixbay.com/knowledge/training/defoliation-lollipopping.html", "markdown_url": "https://genetixbay.com/knowledge/training/defoliation-lollipopping.md", "summary": "Lollipopping strips small branches and leaves from the shaded lower third at or near the flip; defoliation removes fan leaves that shade bud sites or block airflow. In a controlled study on large plants, neither defoliation three weeks before harvest nor lower-branch removal changed flower or cannabinoid yield per plant, and defoliation improved cannabinoid uniformity. Stripping within reason doesn't hurt yield, but in the founder's experience tucking helps more: tuck and train first. Whether tucking beats stripping, and whether defoliation raises cannabinoids, is an open GenetixBay trial question.", "tags": [ "defoliation", "lollipopping", "pruning", "leaf-removal", "airflow", "uniformity" ], "stage": [ "veg", "transition", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Should I defoliate my cannabis plant?", "When should I lollipop?", "Does defoliation increase yield?", "How many leaves can I remove?", "What is the day 21 defoliation?", "Tuck or pluck fan leaves?", "Does defoliation increase THC or cannabinoids?" ], "myths": [], "related": [ "kb-training-scrog", "kb-training-sog", "kb-training-topping", "kb-environment-airflow", "kb-environment-humidity-by-stage", "kb-diseases-botrytis-bud-rot" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-training-fim", "title": "FIM: pinching most of the tip for multiple tops", "category": "training", "category_name": "Training", "slug": "fim", "url": "https://genetixbay.com/knowledge/training/fim.html", "markdown_url": "https://genetixbay.com/knowledge/training/fim.md", "summary": "FIM removes roughly 70–80 % of the newest growth at the tip instead of cutting cleanly above a node. When it works, three to five shoots grow from the same point; when it doesn't, you get one or two, like a sloppy top. It is less predictable than topping and has no controlled research behind its yield claims.", "tags": [ "fim", "pinching", "pruning", "apical-dominance", "colas" ], "stage": [ "veg" ], "systems": [ "any" ], "evidence": "grower_practice", "evidence_name": "Grower practice", "level": "beginner", "qa": [ "What is FIMing?", "FIM vs topping: which gives more colas?", "How much of the tip do I cut for FIM?", "Why did my FIM only grow one top?" ], "myths": [], "related": [ "kb-training-topping", "kb-training-lst", "kb-training-scrog" ], "sources_count": 2, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-training-hst-supercropping", "title": "HST and supercropping: controlled stem crushing", "category": "training", "category_name": "Training", "slug": "hst-supercropping", "url": "https://genetixbay.com/knowledge/training/hst-supercropping.html", "markdown_url": "https://genetixbay.com/knowledge/training/hst-supercropping.md", "summary": "Supercropping pinches and gently crushes a green stem until the inner tissue softens, then bends it over so the tip sits lower. It is used to tame tall shoots in late veg and early stretch. Done right the stem forms a firm knuckle in a few days. Stem snapping gives better buds in the founder's long experience: *Grower practice*, house-endorsed, though no controlled study has measured a potency gain yet. Every cultivar responds differently.", "tags": [ "hst", "supercropping", "high-stress-training", "stretch", "canopy-control" ], "stage": [ "veg", "transition" ], "systems": [ "any" ], "evidence": "grower_practice", "evidence_name": "Grower practice", "level": "intermediate", "qa": [ "What is supercropping?", "When should I supercrop?", "Does supercropping increase THC?", "Does snapping stems give better buds?", "What do I do if I snap a branch?", "Is HST bad for autoflowers?" ], "myths": [], "related": [ "kb-training-lst", "kb-training-topping", "kb-training-scrog", "kb-environment-heat-light-stress" ], "sources_count": 3, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-training-lst", "title": "LST: low-stress training", "category": "training", "category_name": "Training", "slug": "lst", "url": "https://genetixbay.com/knowledge/training/lst.html", "markdown_url": "https://genetixbay.com/knowledge/training/lst.md", "summary": "Low-stress training bends and ties stems outward and down so the plant grows as a flat, even canopy, without cutting anything. It is the safest training method, suits autoflowers, and works with topping and SCROG. Start in early veg, adjust ties every few days, and stop bending hard once stems lignify in mid-stretch.", "tags": [ "lst", "low-stress-training", "tie-down", "canopy", "autoflower" ], "stage": [ "veg", "transition" ], "systems": [ "any" ], "evidence": "grower_practice", "evidence_name": "Grower practice", "level": "beginner", "qa": [ "How do I LST a cannabis plant?", "When should I start low stress training?", "Is LST good for autoflowers?", "Can I LST in flower?", "What do I tie plants down with?" ], "myths": [], "related": [ "kb-training-defoliation-lollipopping", "kb-training-topping", "kb-training-scrog", "kb-training-hst-supercropping", "kb-training-mainlining-manifolding" ], "sources_count": 2, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-training-mainlining-manifolding", "title": "Mainlining and manifolding: building a symmetrical plant", "category": "training", "category_name": "Training", "slug": "mainlining-manifolding", "url": "https://genetixbay.com/knowledge/training/mainlining-manifolding.html", "markdown_url": "https://genetixbay.com/knowledge/training/mainlining-manifolding.md", "summary": "Mainlining (manifolding) tops a young plant down to the third node, removes all lower growth, and then tops each arm repeatedly to build a symmetrical hub feeding 8 or 16 evenly matched colas. It produces a very even canopy at the cost of 2–4 extra weeks of veg. It is grower practice with no controlled studies; the closest research found double pruning increased yield per plant.", "tags": [ "mainlining", "manifolding", "topping", "symmetry", "colas" ], "stage": [ "veg" ], "systems": [ "any" ], "evidence": "grower_practice", "evidence_name": "Grower practice", "level": "advanced", "qa": [ "What is mainlining cannabis?", "How long does mainlining add to veg?", "How many colas can I get from mainlining?", "Mainlining vs topping and LST?" ], "myths": [], "related": [ "kb-training-topping", "kb-training-lst", "kb-training-scrog", "kb-training-defoliation-lollipopping" ], "sources_count": 2, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-training-scrog", "title": "SCROG: screen of green", "category": "training", "category_name": "Training", "slug": "scrog", "url": "https://genetixbay.com/knowledge/training/scrog.html", "markdown_url": "https://genetixbay.com/knowledge/training/scrog.md", "summary": "SCROG uses a horizontal net 20–40 cm above the pots to spread a few plants into a flat, even canopy: shoots are tucked under the net through veg and early stretch, then allowed to grow up through it. It suits small rooms and plant-count limits, at the cost of longer veg. Fill about 70–80 % of the net before flipping, since plants stretch to fill the rest.", "tags": [ "scrog", "screen", "trellis", "net", "canopy", "low-plant-count" ], "stage": [ "veg", "transition", "flower" ], "systems": [ "any" ], "evidence": "grower_practice", "evidence_name": "Grower practice", "level": "intermediate", "qa": [ "How does SCROG work?", "How high should the SCROG net be?", "When do I flip a SCROG to flower?", "SCROG vs SOG: which yields more?", "How many plants for a SCROG?" ], "myths": [], "related": [ "kb-training-lst", "kb-training-topping", "kb-training-sog", "kb-training-defoliation-lollipopping" ], "sources_count": 3, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-training-sog", "title": "SOG: sea of green", "category": "training", "category_name": "Training", "slug": "sog", "url": "https://genetixbay.com/knowledge/training/sog.html", "markdown_url": "https://genetixbay.com/knowledge/training/sog.md", "summary": "Sea of green packs many small plants, usually clones, into the space and flowers them after little or no veg, so each plant makes one main cola. Higher planting density increases yield per square metre but lowers cannabinoid uniformity between plants, according to controlled research. Typical densities are 9–25 plants per m² with 0–14 days of veg; check local plant-count rules first.", "tags": [ "sog", "sea-of-green", "planting-density", "clones", "short-veg" ], "stage": [ "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "What is sea of green?", "How many plants per square metre for SOG?", "How long to veg for SOG?", "Is SOG legal where I live?", "Does higher planting density increase yield?" ], "myths": [], "related": [ "kb-training-scrog", "kb-training-defoliation-lollipopping", "kb-systems-ebb-and-flow", "kb-systems-nft" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-training-topping", "title": "Topping: cutting the main tip for more colas", "category": "training", "category_name": "Training", "slug": "topping", "url": "https://genetixbay.com/knowledge/training/topping.html", "markdown_url": "https://genetixbay.com/knowledge/training/topping.md", "summary": "Topping removes the main growing tip above a node so the two shoots below take over, breaking apical dominance and producing a flatter plant with more main colas. Top healthy plants with 4–6 nodes, cut just above the chosen node, and allow 5–10 days of recovery before flipping to flower. In one controlled study, pruning twice (at transplant and at the switch to flower) gave the highest flower and cannabinoid yield per plant.", "tags": [ "topping", "pruning", "apical-dominance", "canopy", "colas" ], "stage": [ "veg" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "When should I top my cannabis plant?", "Where exactly do I cut when topping?", "Does topping increase yield?", "Can I top autoflowers?", "How many times can I top a plant?", "Topping vs FIM: which is better?" ], "myths": [], "related": [ "kb-training-fim", "kb-training-lst", "kb-training-mainlining-manifolding", "kb-training-scrog", "kb-training-defoliation-lollipopping" ], "sources_count": 3, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-pests-aphids", "title": "Aphids on cannabis: cannabis aphid, green peach aphid and friends", "category": "pests", "category_name": "Pests", "slug": "aphids", "url": "https://genetixbay.com/knowledge/pests/aphids.html", "markdown_url": "https://genetixbay.com/knowledge/pests/aphids.md", "summary": "Aphids are soft-bodied sap feeders that cluster on leaf undersides and stems, shed white skins and drip sticky honeydew; they breed asexually and fast, so catch them early and use parasitoid wasps, predatory midges and lacewings, with soaps or oils only before flower.", "tags": [ "aphids", "cannabis-aphid", "phorodon-cannabis", "myzus-persicae", "honeydew", "ipm", "parasitoids" ], "stage": [ "veg", "transition", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "What are the small pale bugs under my cannabis leaves?", "Why are my leaves sticky?", "How do I get rid of aphids on cannabis?", "What is the cannabis aphid?", "Which beneficial insects eat aphids?" ], "myths": [], "related": [ "kb-pests-root-aphids", "kb-pests-whiteflies", "kb-diagnosis-how-to-diagnose-any-problem", "kb-diseases-hop-latent-viroid-and-viruses", "kb-diseases-botrytis-bud-rot", "kb-diseases-sanitation-and-prevention" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-pests-broad-russet-mites", "title": "Broad mites and hemp russet mites: the invisible ones", "category": "pests", "category_name": "Pests", "slug": "broad-russet-mites", "url": "https://genetixbay.com/knowledge/pests/broad-russet-mites.html", "markdown_url": "https://genetixbay.com/knowledge/pests/broad-russet-mites.md", "summary": "Broad mites (Polyphagotarsonemus latus) twist and harden new growth; hemp russet mites (Aculops cannabicola) bronze leaves and curl edges upward. Both are too small to see without 20x or more, are mistaken for nutrient problems, and are managed by clean stock, quarantine, preventive predatory mites and removal of infested plants.", "tags": [ "broad-mite", "russet-mite", "aculops-cannabicola", "polyphagotarsonemus-latus", "eriophyid", "tarsonemid", "ipm" ], "stage": [ "veg", "transition", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Why are my new leaves twisted and shiny but my feed is fine?", "How do I know if I have russet mites?", "Broad mites or calcium deficiency?", "Can you get rid of russet mites in flower?", "Why are my leaves bronze and curling up?" ], "myths": [], "related": [ "kb-pests-spider-mites", "kb-pests-whiteflies", "kb-diagnosis-yellow-new-growth", "kb-diagnosis-how-to-diagnose-any-problem", "kb-diseases-sanitation-and-prevention", "kb-diseases-hop-latent-viroid-and-viruses" ], "sources_count": 8, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-pests-caterpillars", "title": "Caterpillars and budworms on cannabis", "category": "pests", "category_name": "Pests", "slug": "caterpillars", "url": "https://genetixbay.com/knowledge/pests/caterpillars.html", "markdown_url": "https://genetixbay.com/knowledge/pests/caterpillars.md", "summary": "Caterpillars, mainly corn earworm (Helicoverpa zea) outdoors, bore into buds, leave frass and start bud rot; scout from early flower, use pheromone traps for moth flights, exclude moths with netting, and use Bt (kurstaki or aizawai) while larvae are small, since it must be eaten and breaks down in sunlight within days.", "tags": [ "caterpillars", "budworm", "corn-earworm", "helicoverpa-zea", "hemp-borer", "bt", "bud-rot", "outdoor" ], "stage": [ "flower", "ripen" ], "systems": [ "soil", "living_soil", "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "What is eating my buds?", "Why is there brown mush inside my cola?", "How do I stop budworms on outdoor cannabis?", "Is Bt safe to use in flower?", "When do caterpillars attack cannabis?" ], "myths": [], "related": [ "kb-diseases-botrytis-bud-rot", "kb-diagnosis-how-to-diagnose-any-problem", "kb-pests-aphids", "kb-diseases-sanitation-and-prevention" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-pests-fungus-gnats", "title": "Fungus gnats: the watering problem with wings", "category": "pests", "category_name": "Pests", "slug": "fungus-gnats", "url": "https://genetixbay.com/knowledge/pests/fungus-gnats.html", "markdown_url": "https://genetixbay.com/knowledge/pests/fungus-gnats.md", "summary": "Fungus gnats (Bradysia spp.) breed in constantly wet, organic-rich media; adults are a nuisance but larvae chew roots of seedlings and clones and can open the door to Pythium and Fusarium. Fix the watering first, then use Bti, Steinernema feltiae nematodes or soil predatory mites, and sticky cards to monitor.", "tags": [ "fungus-gnats", "bradysia", "overwatering", "seedlings", "clones", "bti", "nematodes", "stratiolaelaps" ], "stage": [ "seedling", "veg", "flower" ], "systems": [ "soil", "coco", "living_soil", "rockwool" ], "evidence": "established", "evidence_name": "Established", "level": "beginner", "qa": [ "What are the little black flies in my grow?", "Are fungus gnats harmful to cannabis?", "How do I get rid of fungus gnats in soil or coco?", "Do fungus gnats cause root rot?", "Do I need to let my pots dry out for fungus gnats?" ], "myths": [], "related": [ "kb-pests-root-aphids", "kb-pests-thrips", "kb-diagnosis-drooping-overwatering-vs-underwatering", "kb-diagnosis-slow-growth", "kb-diseases-root-rot-pythium", "kb-diseases-fusarium" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-pests-root-aphids", "title": "Root aphids (rice root aphid) on indoor cannabis", "category": "pests", "category_name": "Pests", "slug": "root-aphids", "url": "https://genetixbay.com/knowledge/pests/root-aphids.html", "markdown_url": "https://genetixbay.com/knowledge/pests/root-aphids.md", "summary": "The 'root aphid' of indoor cannabis in North America is mainly the rice root aphid (Rhopalosiphum rufiabdominale); wingless colonies feed on roots and cause slow growth, wilting and yellowing that look like nutrient or watering problems. Confirm by inspecting roots and cards, then rely on sanitation, a plant-free gap between cycles, and soil-applied biologicals.", "tags": [ "root-aphids", "rice-root-aphid", "rhopalosiphum-rufiabdominale", "roots", "slow-growth", "ipm" ], "stage": [ "veg", "transition", "flower" ], "systems": [ "soil", "coco", "rockwool", "living_soil", "dwc", "rdwc" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Why is my plant slowly yellowing and wilting with healthy-looking leaves?", "What are the small bugs on my cannabis roots?", "How do I get rid of root aphids?", "Root aphids or fungus gnats?" ], "myths": [], "related": [ "kb-pests-aphids", "kb-pests-fungus-gnats", "kb-diagnosis-slow-growth", "kb-diagnosis-drooping-overwatering-vs-underwatering", "kb-diagnosis-root-browning-hydro", "kb-diseases-root-rot-pythium" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-pests-spider-mites", "title": "Spider mites on cannabis: ID, lifecycle and IPM", "category": "pests", "category_name": "Pests", "slug": "spider-mites", "url": "https://genetixbay.com/knowledge/pests/spider-mites.html", "markdown_url": "https://genetixbay.com/knowledge/pests/spider-mites.md", "summary": "Twospotted spider mites (Tetranychus urticae) cause pale stippling on leaf tops and webbing at heavy populations; they breed fastest in hot, dry rooms, so control rests on early scouting, cooler and more humid conditions, and predatory mites released before numbers explode, with soaps or oils only before flower.", "tags": [ "spider-mites", "twospotted-spider-mite", "tetranychus-urticae", "ipm", "predatory-mites", "webbing", "stippling" ], "stage": [ "veg", "transition", "flower" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "beginner", "qa": [ "What are the tiny dots on my cannabis leaves?", "How do I get rid of spider mites in flower?", "Which predatory mite should I use for spider mites?", "Is there webbing on my buds from spider mites?", "How fast do spider mites reproduce?" ], "myths": [], "related": [ "kb-pests-broad-russet-mites", "kb-pests-thrips", "kb-diagnosis-rust-spots", "kb-diagnosis-how-to-diagnose-any-problem", "kb-diseases-sanitation-and-prevention" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-pests-thrips", "title": "Thrips on cannabis: silver scars, black specks and how to break the cycle", "category": "pests", "category_name": "Pests", "slug": "thrips", "url": "https://genetixbay.com/knowledge/pests/thrips.html", "markdown_url": "https://genetixbay.com/knowledge/pests/thrips.md", "summary": "Thrips rasp leaf cells and leave silvery scars dotted with black fecal specks; because they pupate in the medium, the fix is a two-level attack: predatory mites and bugs on the foliage plus soil-dwelling predators or nematodes below, backed by blue or yellow sticky cards and clean stock.", "tags": [ "thrips", "western-flower-thrips", "frankliniella-occidentalis", "ipm", "predatory-mites", "orius", "sticky-cards" ], "stage": [ "veg", "transition", "flower" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "beginner", "qa": [ "What are the silver streaks with black dots on my leaves?", "How do I get rid of thrips on cannabis?", "Thrips or spider mites?", "Can I use predatory mites for thrips in flower?", "Why do thrips keep coming back?" ], "myths": [], "related": [ "kb-pests-spider-mites", "kb-pests-fungus-gnats", "kb-pests-whiteflies", "kb-diagnosis-rust-spots", "kb-diagnosis-how-to-diagnose-any-problem", "kb-diseases-sanitation-and-prevention" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-pests-whiteflies", "title": "Whiteflies on cannabis: ID and IPM", "category": "pests", "category_name": "Pests", "slug": "whiteflies", "url": "https://genetixbay.com/knowledge/pests/whiteflies.html", "markdown_url": "https://genetixbay.com/knowledge/pests/whiteflies.md", "summary": "Whiteflies are tiny white moth-like sap feeders that rise in a cloud when you shake a plant; nymphs sit flat under leaves and drip honeydew. Identify the species, monitor with yellow cards, and use Encarsia formosa (greenhouse whitefly) or Eretmocerus (warmer rooms, silverleaf whitefly) plus predatory mites, keeping sprays out of flower.", "tags": [ "whiteflies", "trialeurodes-vaporariorum", "bemisia-tabaci", "honeydew", "encarsia", "eretmocerus", "ipm" ], "stage": [ "veg", "transition", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "What are the tiny white flies on my cannabis?", "How do I get rid of whiteflies indoors?", "Encarsia or Eretmocerus for whiteflies?", "Why are my leaves sticky with black mould?" ], "myths": [], "related": [ "kb-pests-aphids", "kb-pests-broad-russet-mites", "kb-pests-thrips", "kb-diagnosis-how-to-diagnose-any-problem", "kb-diseases-sanitation-and-prevention" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diseases-botrytis-bud-rot", "title": "Botrytis (bud rot / grey mould) in cannabis", "category": "diseases", "category_name": "Diseases", "slug": "botrytis-bud-rot", "url": "https://genetixbay.com/knowledge/diseases/botrytis-bud-rot.html", "markdown_url": "https://genetixbay.com/knowledge/diseases/botrytis-bud-rot.md", "summary": "Bud rot is Botrytis cinerea rotting dense colas from the inside, favoured by cool-to-moderate temperatures (10–27 °C, optimum near 20 °C), high humidity and free water on tissue. There is no cure in flower: prevent it with RH below about 50 % in late flower, dew-point control at lights-off, airflow, open canopies and fast removal of infected buds.", "tags": [ "botrytis", "bud-rot", "grey-mould", "gray-mold", "flower", "humidity", "dew-point", "ipm" ], "stage": [ "flower", "ripen", "harvest", "cure" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "intermediate", "qa": [ "What does bud rot look like on cannabis?", "Why are my cannabis buds turning brown inside?", "How do I stop bud rot spreading on cannabis?", "What humidity prevents bud rot in cannabis?", "Can I save cannabis buds with botrytis?", "Is it safe to smoke cannabis buds with bud rot?" ], "myths": [], "related": [ "kb-diseases-powdery-mildew", "kb-diseases-fusarium", "kb-diseases-sanitation-and-prevention", "kb-pests-caterpillars", "kb-diagnosis-how-to-diagnose-any-problem" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diseases-fusarium", "title": "Fusarium in cannabis: wilt, crown rot and bud rot", "category": "diseases", "category_name": "Diseases", "slug": "fusarium", "url": "https://genetixbay.com/knowledge/diseases/fusarium.html", "markdown_url": "https://genetixbay.com/knowledge/diseases/fusarium.md", "summary": "Fusarium fungi cause three different problems in cannabis: vascular wilt (F. oxysporum), root and crown rot (mainly F. solani), and a pinkish-white bud rot. There is no cure once a plant is infected; remove it, stop root-zone stress, sanitise pots and water, and source clean clones and media.", "tags": [ "fusarium", "wilt", "crown-rot", "root-rot", "bud-rot", "soil-borne", "sanitation", "vascular" ], "stage": [ "seedling", "veg", "flower" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "intermediate", "qa": [ "Why is my cannabis plant wilting on one side?", "What does Fusarium look like in cannabis?", "Why is the inside of my cannabis stem brown?", "Is Fusarium wilt in cannabis curable?", "How can I tell Fusarium from Pythium in cannabis?", "What causes pink mould on cannabis buds?" ], "myths": [], "related": [ "kb-diseases-root-rot-pythium", "kb-diseases-botrytis-bud-rot", "kb-diseases-sanitation-and-prevention", "kb-diagnosis-drooping-overwatering-vs-underwatering", "kb-diagnosis-yellowing-lower-leaves", "kb-pests-fungus-gnats" ], "sources_count": 8, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diseases-hop-latent-viroid-and-viruses", "title": "Hop latent viroid (HLVd, 'dudding') and other cannabis viruses", "category": "diseases", "category_name": "Diseases", "slug": "hop-latent-viroid-and-viruses", "url": "https://genetixbay.com/knowledge/diseases/hop-latent-viroid-and-viruses.html", "markdown_url": "https://genetixbay.com/knowledge/diseases/hop-latent-viroid-and-viruses.md", "summary": "Hop latent viroid is a tiny infectious RNA that spreads through sap on tools, hands, clones, recirculating water and seed, and causes 'dudding': stunting, brittle stems and small, low-resin flowers. There is no cure in a plant. Test mothers (roots and leaves) by RT-PCR/RT-qPCR, discard positives, disinfect tools with bleach or heat (not alcohol), and use meristem tissue culture to rescue valuable genetics.", "tags": [ "hlvd", "hop-latent-viroid", "viroid", "dudding", "virus", "beet-curly-top", "lettuce-chlorosis-virus", "testing", "tissue-culture", "mother-plants" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Is cannabis clone decline real or is it HLVd?", "What is hop latent viroid in cannabis?", "What are the symptoms of HLVd or dudding in cannabis?", "How does HLVd spread between cannabis plants?", "Does alcohol kill hop latent viroid on tools?", "How do I test my cannabis mother plants for HLVd?", "Can you cure HLVd in cannabis?", "Can HLVd spread through cannabis seeds?", "What viruses infect cannabis?" ], "myths": [], "related": [ "kb-breeding-clone-only-preservation", "kb-diseases-sanitation-and-prevention", "kb-diseases-root-rot-pythium", "kb-diagnosis-slow-growth", "kb-diagnosis-how-to-diagnose-any-problem", "kb-pests-whiteflies" ], "sources_count": 8, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diseases-powdery-mildew", "title": "Powdery mildew in cannabis", "category": "diseases", "category_name": "Diseases", "slug": "powdery-mildew", "url": "https://genetixbay.com/knowledge/diseases/powdery-mildew.html", "markdown_url": "https://genetixbay.com/knowledge/diseases/powdery-mildew.md", "summary": "Powdery mildew is a leaf-surface fungus (mainly Golovinomyces ambrosiae) that thrives in still, humid, moderate-temperature canopies and spreads by airborne spores. Prevent it with airflow, stable humidity, clean clones and resistant genetics; treat early in veg with least-toxic contact options, because once it reaches flowers there is no clean fix.", "tags": [ "powdery-mildew", "golovinomyces", "fungus", "foliar", "ipm", "humidity", "airflow", "resistance" ], "stage": [ "veg", "transition", "flower" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "intermediate", "qa": [ "What is the white powder on my cannabis leaves?", "How do I get rid of powdery mildew on cannabis?", "Can I spray for powdery mildew in cannabis flower?", "Is powdery mildew systemic in cannabis?", "What humidity causes powdery mildew on cannabis?", "Are there powdery mildew resistant cannabis strains?" ], "myths": [], "related": [ "kb-diagnosis-white-powder-on-leaves", "kb-diseases-botrytis-bud-rot", "kb-diseases-sanitation-and-prevention", "kb-diagnosis-how-to-diagnose-any-problem" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diseases-root-rot-pythium", "title": "Root rot and Pythium in cannabis", "category": "diseases", "category_name": "Diseases", "slug": "root-rot-pythium", "url": "https://genetixbay.com/knowledge/diseases/root-rot-pythium.html", "markdown_url": "https://genetixbay.com/knowledge/diseases/root-rot-pythium.md", "summary": "Pythium root rot is a water mould that thrives in warm, low-oxygen root zones and swims between plants in recirculating water. Brown, slimy roots whose outer layer slides off, plus wilting with a wet root zone, are the signature. Fix the root-zone conditions first: solution at about 18–21 °C (65–70 °F), high dissolved oxygen, clean water and no overwatering; then remove dead roots and re-establish beneficial microbes.", "tags": [ "root-rot", "pythium", "hydroponics", "dwc", "rdwc", "coco", "dissolved-oxygen", "water-temperature", "oomycete" ], "stage": [ "seedling", "veg", "flower" ], "systems": [ "dwc", "rdwc", "nft", "ebb_flow", "drip", "aero", "coco", "rockwool", "soil" ], "evidence": "established", "evidence_name": "Established", "level": "intermediate", "qa": [ "Why are my DWC cannabis roots brown and slimy?", "What water temperature prevents Pythium root rot?", "How do I treat Pythium in cannabis hydroponics?", "Is brown root colour from nutrients or root rot?", "Can I use hydrogen peroxide for cannabis root rot?", "Should a cannabis hydro reservoir use beneficial microbes or be sterile?", "Why is my cannabis plant wilting when the soil is wet?" ], "myths": [], "related": [ "kb-diagnosis-root-browning-hydro", "kb-diagnosis-drooping-overwatering-vs-underwatering", "kb-diseases-fusarium", "kb-diseases-hop-latent-viroid-and-viruses", "kb-diseases-sanitation-and-prevention", "kb-pests-fungus-gnats" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diseases-sanitation-and-prevention", "title": "Sanitation and disease prevention for cannabis grows", "category": "diseases", "category_name": "Diseases", "slug": "sanitation-and-prevention", "url": "https://genetixbay.com/knowledge/diseases/sanitation-and-prevention.html", "markdown_url": "https://genetixbay.com/knowledge/diseases/sanitation-and-prevention.md", "summary": "Most cannabis disease problems are brought in on clones, tools, hands, media or water, and then helped along by humid, stagnant rooms. Quarantine and test incoming plants, work clean-to-dirty, clean then disinfect with the right chemical class for the pathogen (bleach or hypochlorous acid or heat for viroids; alcohol and peroxide do not inactivate HLVd), treat recirculating water, and keep the climate out of the disease zone.", "tags": [ "sanitation", "prevention", "quarantine", "disinfectant", "bleach", "hypochlorous-acid", "hlvd", "clean-room", "water-treatment", "ipm" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "How do I sterilise my cannabis grow room between cycles?", "What kills hop latent viroid on scissors?", "How long should I quarantine new cannabis clones?", "Which is better for cleaning grow tools, bleach, hydrogen peroxide or alcohol?", "How do I prevent powdery mildew and bud rot in a cannabis grow?", "Is it safe to mix bleach with other cleaners in a grow room?" ], "myths": [], "related": [ "kb-diseases-hop-latent-viroid-and-viruses", "kb-diseases-powdery-mildew", "kb-diseases-botrytis-bud-rot", "kb-diseases-root-rot-pythium", "kb-diseases-fusarium", "kb-diseases-septoria-leaf-spot" ], "sources_count": 9, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diseases-septoria-leaf-spot", "title": "Septoria leaf spot (yellow leaf spot) in cannabis", "category": "diseases", "category_name": "Diseases", "slug": "septoria-leaf-spot", "url": "https://genetixbay.com/knowledge/diseases/septoria-leaf-spot.html", "markdown_url": "https://genetixbay.com/knowledge/diseases/septoria-leaf-spot.md", "summary": "Septoria leaf spot (Septoria cannabis) starts as small brown spots with bright yellow halos on lower, older leaves and climbs the plant in wet, humid weather by rain and water splash. It is mainly an outdoor and greenhouse problem; manage it with clean lower canopies, dry foliage, mulch, airflow and debris removal, and protectants only where registered.", "tags": [ "septoria", "leaf-spot", "yellow-leaf-spot", "fungus", "outdoor", "rain-splash", "lower-leaves" ], "stage": [ "veg", "flower" ], "systems": [ "soil", "living_soil", "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "What causes brown spots with yellow halos on lower cannabis leaves?", "What is septoria leaf spot on cannabis?", "Is it leaf spot disease or a nutrient deficiency on my cannabis?", "How do I stop leaf spot spreading up my cannabis plant?", "Does septoria affect cannabis buds or yield?" ], "myths": [], "related": [ "kb-diagnosis-rust-spots", "kb-diagnosis-yellowing-lower-leaves", "kb-diseases-sanitation-and-prevention", "kb-diseases-powdery-mildew", "kb-diagnosis-how-to-diagnose-any-problem" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diagnosis-brown-burnt-tips", "title": "Brown or burnt leaf tips on cannabis: a differential", "category": "diagnosis", "category_name": "Diagnosis", "slug": "brown-burnt-tips", "url": "https://genetixbay.com/knowledge/diagnosis/brown-burnt-tips.html", "markdown_url": "https://genetixbay.com/knowledge/diagnosis/brown-burnt-tips.md", "summary": "Crispy brown tips on otherwise healthy leaves usually mean too much salt in the root zone (EC too high, or salts building up because of low runoff or drying out), not a deficiency. Check runoff or reservoir EC against input first, then watering rhythm, then heat and low humidity, and only then K or B disorders.", "tags": [ "tip-burn", "nutrient-burn", "ec", "salts", "potassium", "boron", "heat", "low-humidity" ], "stage": [ "seedling", "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Why are the tips of my cannabis leaves brown and crispy?", "Is brown tip burn on cannabis nutrient burn?", "Why do cannabis seedlings get burnt tips?", "How does high EC cause tip burn on cannabis?", "What is the difference between brown leaf edges and brown tips on cannabis?", "How do I flush salt build-up from cannabis pots?" ], "myths": [], "related": [ "kb-harvest-cure-flush-debate", "kb-ph-ec-runoff-testing", "kb-diagnosis-how-to-diagnose-any-problem", "kb-diagnosis-clawing-leaves", "kb-diagnosis-yellowing-lower-leaves", "kb-diagnosis-rust-spots" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diagnosis-root-browning-hydro", "title": "Brown roots in hydroponics (DWC, RDWC, NFT): a differential", "category": "diagnosis", "category_name": "Diagnosis", "slug": "root-browning-hydro", "url": "https://genetixbay.com/knowledge/diagnosis/root-browning-hydro.html", "markdown_url": "https://genetixbay.com/knowledge/diagnosis/root-browning-hydro.md", "summary": "Healthy hydro roots are white to cream and firm. Brown roots that are still firm and odourless are often just stained by nutrients or additives; brown, slimy, smelly roots whose outer layer slips off are root rot, usually Pythium, favoured by warm, oxygen-poor solution. Check solution temperature and dissolved oxygen first, then root texture and smell.", "tags": [ "root-rot", "pythium", "fusarium", "dwc", "rdwc", "dissolved-oxygen", "solution-temperature", "staining", "hlvd" ], "stage": [ "seedling", "veg", "flower" ], "systems": [ "dwc", "rdwc", "nft", "ebb_flow", "aero" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Why are my DWC roots turning brown?", "What causes brown slimy roots in cannabis hydroponics?", "How can I tell root rot from stained roots in hydro?", "What water temperature prevents root rot in cannabis hydro?", "Why does my hydro reservoir smell and my cannabis plants wilt?" ], "myths": [], "related": [ "kb-diagnosis-how-to-diagnose-any-problem", "kb-diagnosis-drooping-overwatering-vs-underwatering", "kb-diagnosis-yellowing-lower-leaves", "kb-diagnosis-slow-growth", "kb-diseases-root-rot-pythium", "kb-diseases-fusarium" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diagnosis-clawing-leaves", "title": "Clawing leaves on cannabis: a differential", "category": "diagnosis", "category_name": "Diagnosis", "slug": "clawing-leaves", "url": "https://genetixbay.com/knowledge/diagnosis/clawing-leaves.html", "markdown_url": "https://genetixbay.com/knowledge/diagnosis/clawing-leaves.md", "summary": "Leaves that curl down at the tips like a talon, especially if dark green and glossy, most often mean excess nitrogen and high EC, or a waterlogged, oxygen-starved root zone. Check watering and runoff EC first; distorted, crinkled clawing on new growth instead points to broad mites, calcium/boron problems or a viroid.", "tags": [ "claw", "nitrogen-toxicity", "overwatering", "ec", "root-zone", "heat", "broad-mites" ], "stage": [ "veg", "transition", "flower" ], "systems": [ "any" ], "evidence": "grower_practice", "evidence_name": "Grower practice", "level": "intermediate", "qa": [ "Why are my cannabis leaves clawing down?", "Why are dark green cannabis leaves curling down at the tips?", "Is the claw always nitrogen toxicity in cannabis?", "What makes cannabis leaves point down like eagle talons?", "Why do cannabis leaves claw after a transplant?" ], "myths": [], "related": [ "kb-diagnosis-how-to-diagnose-any-problem", "kb-diagnosis-brown-burnt-tips", "kb-diagnosis-drooping-overwatering-vs-underwatering", "kb-diagnosis-taco-canoeing-leaves", "kb-pests-broad-russet-mites", "kb-diseases-hop-latent-viroid-and-viruses" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diagnosis-drooping-overwatering-vs-underwatering", "title": "Drooping cannabis: overwatering vs underwatering", "category": "diagnosis", "category_name": "Diagnosis", "slug": "drooping-overwatering-vs-underwatering", "url": "https://genetixbay.com/knowledge/diagnosis/drooping-overwatering-vs-underwatering.html", "markdown_url": "https://genetixbay.com/knowledge/diagnosis/drooping-overwatering-vs-underwatering.md", "summary": "Lift the pot: a heavy pot with firm, swollen-looking drooping leaves is overwatered (roots short of oxygen); a light pot with limp, papery leaves is underwatered. If the medium is moist and the plant still wilts, especially one plant at a time or in hydro, suspect root rot or vascular wilt and look at the roots.", "tags": [ "drooping", "wilting", "overwatering", "underwatering", "root-zone", "oxygen", "root-rot", "fusarium" ], "stage": [ "seedling", "veg", "flower" ], "systems": [ "soil", "coco", "rockwool", "dwc", "rdwc", "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Is my cannabis overwatered or underwatered?", "Why is my cannabis plant drooping after watering?", "Why are cannabis leaves drooping when the soil is wet?", "How often should I water cannabis in fabric pots?", "Why is my cannabis plant wilting in DWC?" ], "myths": [], "related": [ "kb-diagnosis-how-to-diagnose-any-problem", "kb-diagnosis-root-browning-hydro", "kb-diagnosis-yellowing-lower-leaves", "kb-diagnosis-clawing-leaves", "kb-diseases-root-rot-pythium", "kb-diseases-fusarium" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diagnosis-foxtails", "title": "Foxtailing buds on cannabis: genetics or stress?", "category": "diagnosis", "category_name": "Diagnosis", "slug": "foxtails", "url": "https://genetixbay.com/knowledge/diagnosis/foxtails.html", "markdown_url": "https://genetixbay.com/knowledge/diagnosis/foxtails.md", "summary": "Foxtails (new calyx spires growing out of mature buds) are either a cultivar trait, which appears evenly through the canopy, or a stress response to heat and intense light, which shows mostly on the top colas nearest the fixture. Measure canopy leaf temperature and PPFD at the tops; evidence is mainly grower observation.", "tags": [ "foxtail", "buds", "heat-stress", "light-stress", "genetics", "late-flower" ], "stage": [ "flower", "ripen" ], "systems": [ "any" ], "evidence": "grower_practice", "evidence_name": "Grower practice", "level": "intermediate", "qa": [ "Why are my cannabis buds foxtailing?", "Is foxtailing on cannabis caused by heat or light?", "Is foxtailing in late flower genetic?", "Do foxtails mean my cannabis plant is a hermaphrodite?", "How can I prevent foxtails on cannabis?" ], "myths": [], "related": [ "kb-diagnosis-how-to-diagnose-any-problem", "kb-diagnosis-taco-canoeing-leaves", "kb-diagnosis-stretching", "kb-diagnosis-hermaphrodites" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diagnosis-hermaphrodites", "title": "Hermaphrodite cannabis (bananas and nanners): what to do", "category": "diagnosis", "category_name": "Diagnosis", "slug": "hermaphrodites", "url": "https://genetixbay.com/knowledge/diagnosis/hermaphrodites.html", "markdown_url": "https://genetixbay.com/knowledge/diagnosis/hermaphrodites.md", "summary": "Hermaphroditic flowers are anthers (often banana-shaped) or pollen sacs forming on a female plant. Cannabis is a dioecious species, and a well-bred female should stay female; herm-prone plants are mainly the product of bad breeding (repeated selfing, careless feminising, untested 'pollen chucker' seed). Stress such as light leaks or heat reveals that weakness rather than causing it in sound genetics. Fix the environment, remove the plant if it sheds pollen, and never keep it as a mother or breed from it.", "tags": [ "hermaphrodite", "intersex", "bananas", "nanners", "anthers", "light-leaks", "stress", "seeds", "genetics", "breeding-ethics", "culling" ], "stage": [ "transition", "flower", "ripen" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "My cannabis plant is growing bananas: what do I do?", "Why did my cannabis plant turn hermaphrodite?", "Are cannabis hermaphrodites genetic or caused by stress?", "Can light leaks cause cannabis hermaphrodites?", "Are nanners in late cannabis flower a problem?", "Will a hermaphrodite pollinate my whole cannabis room?", "Should I keep or breed a cannabis plant that hermed?", "Are late-flower bananas normal on cannabis?", "Is it OK to have a few nanners at the end of cannabis flower?" ], "myths": [ "Late-flower bananas are normal", "A herm is fine if it's the best plant you've grown" ], "related": [ "kb-breeding-breeders-vs-pollen-chuckers", "kb-basics-sex-male-female-hermaphrodite", "kb-breeding-s1-selfing", "kb-breeding-feminised-seed-sex-reversal", "kb-breeding-selection-pheno-hunting", "kb-breeding-record-keeping-naming-ethics" ], "sources_count": 10, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diagnosis-how-to-diagnose-any-problem", "title": "How to diagnose any cannabis plant problem", "category": "diagnosis", "category_name": "Diagnosis", "slug": "how-to-diagnose-any-problem", "url": "https://genetixbay.com/knowledge/diagnosis/how-to-diagnose-any-problem.html", "markdown_url": "https://genetixbay.com/knowledge/diagnosis/how-to-diagnose-any-problem.md", "summary": "Diagnose in a fixed order: confirm it is a real problem, note where on the plant it started (old vs new growth) and the pattern, then rule out root zone and pH, then environment and light, then pests and disease, and only then blame a nutrient. Change one thing at a time and judge the fix on new growth.", "tags": [ "diagnosis", "method", "ph", "ec", "root-zone", "deficiency", "pests", "disease", "environment" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "How do I figure out what is wrong with my cannabis plant?", "Is it a nutrient deficiency or a pH problem?", "What should I check first when my cannabis plant looks sick?", "Why do growers say check pH before adding nutrients to cannabis?", "What does it mean when old cannabis leaves or new leaves show symptoms first?" ], "myths": [], "related": [ "kb-harvest-cure-flush-debate", "kb-diagnosis-yellowing-lower-leaves", "kb-diagnosis-yellow-new-growth", "kb-diagnosis-brown-burnt-tips", "kb-diagnosis-drooping-overwatering-vs-underwatering", "kb-diagnosis-root-browning-hydro" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diagnosis-purple-stems-leaves", "title": "Purple or red stems and leaves on cannabis: a differential", "category": "diagnosis", "category_name": "Diagnosis", "slug": "purple-stems-leaves", "url": "https://genetixbay.com/knowledge/diagnosis/purple-stems-leaves.html", "markdown_url": "https://genetixbay.com/knowledge/diagnosis/purple-stems-leaves.md", "summary": "Purple or red stems and petioles on a healthy, growing plant are usually genetics, cool nights or bright light, and need no fix. Treat it as a problem only when it comes with something else: lower-leaf yellowing (nitrogen), dark or bronzed spotting on old leaves (phosphorus), or slow growth with a cold or wet root zone. Check root-zone temperature and pH before adding phosphorus.", "tags": [ "purple", "red-stems", "anthocyanin", "phosphorus", "nitrogen", "cold", "genetics", "light" ], "stage": [ "seedling", "veg", "flower", "ripen" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Why are my cannabis stems purple?", "Are red cannabis petioles a sign of phosphorus deficiency?", "Why do cannabis leaves turn purple in late flower?", "Do cold nights make cannabis turn purple?", "Should I add phosphorus to fix purple cannabis stems?" ], "myths": [], "related": [ "kb-diagnosis-how-to-diagnose-any-problem", "kb-diagnosis-yellowing-lower-leaves", "kb-diagnosis-rust-spots", "kb-diagnosis-slow-growth" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diagnosis-rust-spots", "title": "Rust-coloured spots on cannabis leaves: a differential", "category": "diagnosis", "category_name": "Diagnosis", "slug": "rust-spots", "url": "https://genetixbay.com/knowledge/diagnosis/rust-spots.html", "markdown_url": "https://genetixbay.com/knowledge/diagnosis/rust-spots.md", "summary": "Rusty brown spots are most often a calcium or phosphorus uptake problem driven by pH or root-zone stress, but leaf septoria (spots with yellow halos on lower leaves, spreading in humidity) and spider-mite stippling look similar. Check pH and root zone, then turn the leaf over with a hand lens, then decide between Ca, P, Mg/Mn and disease.", "tags": [ "spots", "calcium", "phosphorus", "magnesium", "manganese", "septoria", "spider-mites", "ph" ], "stage": [ "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Why does my cannabis have rust spots on the leaves?", "Are brown spots on cannabis leaves from calcium or disease?", "What causes rusty spots with a yellow halo on cannabis leaves?", "Why do cannabis plants in coco get brown spots on lower leaves?", "Is it calcium deficiency or septoria on my cannabis?" ], "myths": [], "related": [ "kb-diagnosis-how-to-diagnose-any-problem", "kb-diagnosis-yellowing-lower-leaves", "kb-diagnosis-brown-burnt-tips", "kb-diseases-septoria-leaf-spot", "kb-pests-spider-mites", "kb-pests-broad-russet-mites" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diagnosis-slow-growth", "title": "Slow or stunted cannabis growth: a differential", "category": "diagnosis", "category_name": "Diagnosis", "slug": "slow-growth", "url": "https://genetixbay.com/knowledge/diagnosis/slow-growth.html", "markdown_url": "https://genetixbay.com/knowledge/diagnosis/slow-growth.md", "summary": "When a plant just isn't growing, the cause is usually the root zone (overwatering, cold, small or rotting roots), too little light, or a cool room; nutrient shortages come later. Plants that stay stunted with small leaves and short internodes while neighbours thrive should be tested for hop latent viroid and checked for root aphids.", "tags": [ "slow-growth", "stunting", "root-zone", "light", "temperature", "hlvd", "root-aphids", "overwatering" ], "stage": [ "seedling", "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Why is my cannabis growing so slowly?", "Why did my cannabis seedling stop growing?", "Why is my cannabis plant stunted with small leaves?", "Why is my cannabis clone not growing after rooting?", "Is my cannabis plant stunted by hop latent viroid?" ], "myths": [], "related": [ "kb-diagnosis-how-to-diagnose-any-problem", "kb-diagnosis-drooping-overwatering-vs-underwatering", "kb-diagnosis-yellow-new-growth", "kb-diagnosis-root-browning-hydro", "kb-diseases-hop-latent-viroid-and-viruses", "kb-pests-root-aphids" ], "sources_count": 7, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diagnosis-stretching", "title": "Stretchy, leggy cannabis: a differential", "category": "diagnosis", "category_name": "Diagnosis", "slug": "stretching", "url": "https://genetixbay.com/knowledge/diagnosis/stretching.html", "markdown_url": "https://genetixbay.com/knowledge/diagnosis/stretching.md", "summary": "Long internodes and thin stems mean the plant is reaching for light: PPFD too low, light too far away, a low red-to-far-red ratio (shade or crowding), or warm days relative to nights. Some stretch in the first 2–3 weeks after the switch to 12/12 is normal and cultivar dependent. Measure PPFD and day/night temperatures before blaming genetics.", "tags": [ "stretch", "internodes", "light", "far-red", "temperature", "dif", "seedlings", "flower-stretch" ], "stage": [ "seedling", "veg", "transition" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Why is my cannabis seedling so stretched?", "Why is my cannabis plant leggy with long gaps between nodes?", "How much do cannabis plants stretch in flower?", "Does far-red light cause cannabis stretching?", "How can I stop cannabis from stretching?" ], "myths": [], "related": [ "kb-diagnosis-how-to-diagnose-any-problem", "kb-diagnosis-slow-growth", "kb-diagnosis-foxtails", "kb-diagnosis-taco-canoeing-leaves" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diagnosis-taco-canoeing-leaves", "title": "Taco or canoeing leaves on cannabis: a differential", "category": "diagnosis", "category_name": "Diagnosis", "slug": "taco-canoeing-leaves", "url": "https://genetixbay.com/knowledge/diagnosis/taco-canoeing-leaves.html", "markdown_url": "https://genetixbay.com/knowledge/diagnosis/taco-canoeing-leaves.md", "summary": "Leaflets folding upward along the midrib (taco, canoe) on the top of the canopy are almost always heat or light stress, often with low humidity (high VPD). Measure leaf temperature, PPFD and RH at the canopy before anything else; if the whole plant is affected, check the root zone, then calcium and magnesium.", "tags": [ "taco", "canoe", "heat-stress", "light-stress", "vpd", "humidity", "calcium", "root-zone" ], "stage": [ "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Why are my cannabis leaves folding up like a taco?", "Why are cannabis leaves canoeing under an LED?", "Why are the edges of my cannabis leaves curling up?", "Is taco leaf on cannabis heat stress or calcium deficiency?", "What VPD stops cannabis leaves curling?" ], "myths": [], "related": [ "kb-diagnosis-how-to-diagnose-any-problem", "kb-diagnosis-brown-burnt-tips", "kb-diagnosis-clawing-leaves", "kb-diagnosis-foxtails", "kb-diagnosis-yellow-new-growth", "kb-pests-broad-russet-mites" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diagnosis-white-powder-on-leaves", "title": "White powder or white spots on cannabis leaves: a differential", "category": "diagnosis", "category_name": "Diagnosis", "slug": "white-powder-on-leaves", "url": "https://genetixbay.com/knowledge/diagnosis/white-powder-on-leaves.html", "markdown_url": "https://genetixbay.com/knowledge/diagnosis/white-powder-on-leaves.md", "summary": "Flour-like circular white patches that smear off and come back are powdery mildew until proven otherwise. Rule out spray or hard-water residue (on the surfaces you sprayed, dries in drip lines), trichomes (on sugar leaves and buds, glassy under a lens), silvery thrips scarring and mite stippling. Confirm with a 20-60x lens before treating.", "tags": [ "white-powder", "powdery-mildew", "residue", "trichomes", "thrips", "spider-mites", "whiteflies", "salts" ], "stage": [ "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "What is the white powder on my cannabis leaves?", "Is it powdery mildew or trichomes on my cannabis?", "Why are there white spots on cannabis leaves after spraying?", "What causes silver streaks on cannabis leaves?", "How do I confirm powdery mildew on cannabis?" ], "myths": [], "related": [ "kb-diagnosis-how-to-diagnose-any-problem", "kb-diagnosis-rust-spots", "kb-diseases-powdery-mildew", "kb-diseases-botrytis-bud-rot", "kb-pests-thrips", "kb-pests-spider-mites" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diagnosis-yellow-new-growth", "title": "Yellow new growth on cannabis: a differential", "category": "diagnosis", "category_name": "Diagnosis", "slug": "yellow-new-growth", "url": "https://genetixbay.com/knowledge/diagnosis/yellow-new-growth.html", "markdown_url": "https://genetixbay.com/knowledge/diagnosis/yellow-new-growth.md", "summary": "Yellowing at the top of the plant points to an immobile nutrient (Fe, S, Mn, Zn, Cu, B, Ca) that the roots are failing to deliver, and the usual cause is high root-zone pH or a wet, cold or damaged root zone rather than a lack of fertiliser. Rule out light bleaching, broad/russet mites and viroid stunting before adding micronutrients.", "tags": [ "yellowing", "new-growth", "iron", "sulfur", "manganese", "zinc", "ph", "light-bleaching", "broad-mites", "hlvd" ], "stage": [ "veg", "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Why are the new leaves on my cannabis yellow?", "Why is the top of my cannabis plant yellow but the bottom green?", "Is yellow new growth on cannabis iron deficiency?", "Why are the tops of my cannabis bleached white under an LED?", "What causes twisted yellow new growth on cannabis?" ], "myths": [], "related": [ "kb-diagnosis-how-to-diagnose-any-problem", "kb-diagnosis-yellowing-lower-leaves", "kb-diagnosis-slow-growth", "kb-diagnosis-taco-canoeing-leaves", "kb-pests-broad-russet-mites", "kb-diseases-hop-latent-viroid-and-viruses" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-diagnosis-yellowing-lower-leaves", "title": "Yellowing lower leaves on cannabis: a differential", "category": "diagnosis", "category_name": "Diagnosis", "slug": "yellowing-lower-leaves", "url": "https://genetixbay.com/knowledge/diagnosis/yellowing-lower-leaves.html", "markdown_url": "https://genetixbay.com/knowledge/diagnosis/yellowing-lower-leaves.md", "summary": "Lower-leaf yellowing is usually nitrogen shortage or, far more often, roots that cannot take nitrogen up (overwatering, cold or rotting roots, pH out of range). Uniform yellow climbing from the bottom suggests N; green veins with yellow between them suggests Mg; yellow-then-brown margins suggest K. In late flower, gradual fade is normal.", "tags": [ "yellowing", "chlorosis", "nitrogen", "magnesium", "potassium", "overwatering", "ph", "senescence" ], "stage": [ "veg", "flower", "ripen" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Why are the bottom leaves of my cannabis turning yellow?", "Is lower leaf yellowing on cannabis nitrogen deficiency?", "Why are the bottom cannabis leaves yellow with green veins?", "Is yellowing normal in late cannabis flower?", "Should I add more nitrogen if my cannabis lower leaves are yellow?" ], "myths": [], "related": [ "kb-diagnosis-how-to-diagnose-any-problem", "kb-diagnosis-yellow-new-growth", "kb-diagnosis-drooping-overwatering-vs-underwatering", "kb-diagnosis-rust-spots", "kb-diagnosis-root-browning-hydro", "kb-pests-root-aphids" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-harvest-cure-curing-burping", "title": "Curing and burping: jars, humidity and how long", "category": "harvest-cure", "category_name": "Harvest and cure", "slug": "curing-burping", "url": "https://genetixbay.com/knowledge/harvest-cure/curing-burping.html", "markdown_url": "https://genetixbay.com/knowledge/harvest-cure/curing-burping.md", "summary": "Curing is a slow, steady decline in the bud's moisture content and water activity, not a constant hold: start around aw 0.62–0.65 and let it settle towards 0.55–0.58 over two to eight weeks, burping daily at first, then weekly. Jar RH is only a proxy for the bud, valid once a sealed jar has equilibrated (aw ≈ RH / 100). Check with the stem snap, an equilibrated hygrometer and weight. Humidity packs are a marketing gimmick; if a jar is too dry, add a fresh bud.", "tags": [ "curing", "burping", "jars", "humidity-packs", "water-activity", "moisture-content", "smoothness", "water-curing" ], "stage": [ "cure" ], "systems": [ "any" ], "evidence": "grower_practice", "evidence_name": "Grower practice", "level": "beginner", "qa": [ "How long should I cure cannabis?", "How often should I burp jars?", "What humidity should my curing jars be?", "What water activity should cured buds be?", "What moisture content should cured cannabis have?", "How do I know my buds are dry enough to jar?", "Do humidity packs work for curing?", "Should jar humidity stay constant during a cure?", "Is water curing worth it?", "Why does my cure smell like hay?", "Can curing fix a bad dry?" ], "myths": [ "Two-way humidity packs make a better cure" ], "related": [ "kb-harvest-cure-drying", "kb-harvest-cure-long-term-storage", "kb-harvest-cure-flush-debate" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-harvest-cure-drying", "title": "Drying cannabis: the 60/60 method and water activity", "category": "harvest-cure", "category_name": "Harvest and cure", "slug": "drying", "url": "https://genetixbay.com/knowledge/harvest-cure/drying.html", "markdown_url": "https://genetixbay.com/knowledge/harvest-cure/drying.md", "summary": "Dry slowly and in the dark at about 15–21 °C (60–70 °F) and 55–62 % RH, the popular 60/60 target, for 7–14 days until small stems snap and buds reach a water activity of about 0.60–0.65. ASTM D8197 sets 0.55–0.65 aw as the range that protects against mould without making flower brittle. Judge the bud (stem snap, an equilibrated jar reading, weight), not the room. Wet vs dry trim is grower preference. Fast, warm drying loses volatile monoterpenes, and wet, still air grows mould.", "tags": [ "drying", "60-60", "water-activity", "moisture-content", "humidity", "terpenes", "mould", "hang-dry", "wet-trim", "dry-trim" ], "stage": [ "harvest" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Is freeze drying better for cannabis?", "Why does my weed smell like hay?", "What is the 60/60 drying method?", "How long should cannabis dry?", "What humidity and temperature for drying?", "What water activity should dried cannabis have?", "Should I wet trim or dry trim?", "Is dry trimming better than wet trimming?", "How much weight does cannabis lose when drying?", "My buds dried in 3 days, are they ruined?" ], "myths": [], "related": [ "kb-harvest-cure-curing-burping", "kb-harvest-cure-long-term-storage", "kb-harvest-cure-trichome-ripeness", "kb-environment-humidity-by-stage", "kb-diseases-botrytis-bud-rot" ], "sources_count": 7, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-harvest-cure-irradiated-cannabis", "title": "Irradiated cannabis: gamma, e-beam, X-ray, ozone, RF and what they do to your weed", "category": "harvest-cure", "category_name": "Harvest and cure", "slug": "irradiated-cannabis", "url": "https://genetixbay.com/knowledge/harvest-cure/irradiated-cannabis.html", "markdown_url": "https://genetixbay.com/knowledge/harvest-cure/irradiated-cannabis.md", "summary": "Much legal cannabis is decontaminated after harvest so it can pass microbial limits. That means ionising radiation (gamma from cobalt-60, electron beam, X-ray), or ozone, cold plasma, radio-frequency heating, UV or steam. Irradiation doesn't make flower radioactive. At typical doses (2.5–20 kGy) studies find no meaningful change in total THC or CBD. Effects on terpenes range from nothing measurable to 10–20 % losses of volatile monoterpenes, up to 38 % for one compound. Killing mould doesn't remove mycotoxins it has already made. Disclosure rules are patchy: Canada requires the irradiation symbol on edibles but not on dried flower, Washington discloses remediation to consumers only on request, and Nevada has a treatment-label rule. Most places tell the shopper nothing. Growing your own, where legal, with clean IPM and a proper dry avoids the issue.", "tags": [ "irradiation", "gamma", "electron-beam", "x-ray", "ozone", "cold-plasma", "radio-frequency", "uv-c", "decontamination", "remediation", "microbial-testing", "yeast-and-mould", "aspergillus", "mycotoxins", "terpenes", "labelling", "consumer" ], "stage": [ "harvest", "cure" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Is legal weed irradiated?", "Is irradiated weed radioactive?", "Does irradiation destroy terpenes?", "Does irradiation lower THC?", "Why is cannabis irradiated?", "What is e-beam cannabis?", "What is remediated cannabis?", "Do dispensaries have to tell you if weed is irradiated?", "Is irradiated cannabis labelled in Canada?", "Does ozone treatment ruin cannabis?", "What is RF decontamination of cannabis?", "What are the microbial limits for cannabis?", "Does irradiation remove mycotoxins?", "How can I tell if my cannabis was irradiated?", "Is medical cannabis irradiated?" ], "myths": [ "Irradiated weed is radioactive", "Irradiation has no effect on terpenes", "A passing retest means the mould problem is gone" ], "related": [ "kb-harvest-cure-drying", "kb-harvest-cure-curing-burping", "kb-harvest-cure-long-term-storage", "kb-diseases-botrytis-bud-rot", "kb-diseases-sanitation-and-prevention", "kb-basics-buyer-beware-label-claims" ], "sources_count": 34, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-harvest-cure-long-term-storage", "title": "Long-term storage: keeping cured flower potent and aromatic", "category": "harvest-cure", "category_name": "Harvest and cure", "slug": "long-term-storage", "url": "https://genetixbay.com/knowledge/harvest-cure/long-term-storage.html", "markdown_url": "https://genetixbay.com/knowledge/harvest-cure/long-term-storage.md", "summary": "Light is the biggest single cause of cannabinoid loss in storage, air oxidation turns THC into CBN, and warmth and humidity speed both and invite mould. Store cured flower in full, airtight, opaque glass with the bud at aw 0.55–0.65 (an equilibrated jar reading), cool and dark; skip humidity packs, a marketing gimmick. Kept that way it is reasonably stable for one to two years; at room temperature over several years THC loss can be near total. Freezing is possible but makes trichomes brittle.", "tags": [ "storage", "thc-degradation", "cbn", "light", "oxygen", "temperature", "freezing", "water-activity", "humidity-packs" ], "stage": [ "cure" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Should I store cannabis with humidity packs?", "How long does cured cannabis stay good?", "Does cannabis lose potency over time?", "Should I store cannabis in the freezer?", "Why does old weed turn into CBN?", "What is the best container for storing buds?" ], "myths": [], "related": [ "kb-harvest-cure-curing-burping", "kb-harvest-cure-drying", "kb-harvest-cure-trichome-ripeness" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-harvest-cure-flush-debate", "title": "Pre-harvest flushing: a myth that costs you yield and resin", "category": "harvest-cure", "category_name": "Harvest and cure", "slug": "flush-debate", "url": "https://genetixbay.com/knowledge/harvest-cure/flush-debate.html", "markdown_url": "https://genetixbay.com/knowledge/harvest-cure/flush-debate.md", "summary": "Pre-harvest flushing is a myth, and a harmful one. Starving the plant of nutrients in its last weeks takes food away during the phase when it is packing on most of its final weight, trichomes and resin, so it costs yield and resin and gives nothing back: controlled studies found no gain in flower quality, minerals or cannabinoids, and longer nutrient withdrawal tended to cut dry mass and cannabinoid yield. Cannabis stores what it takes up in its tissue, and plain water at the end does not wash it out. Feed through to harvest at stage-appropriate strength; taste and ash are made by plant health, not overfeeding, and slow drying and proper curing. The one valid flush treats the medium, not the plant: a root-zone flush to wash out accumulated salts, at any stage.", "tags": [ "flush", "flushing", "pre-harvest", "ash", "taste", "nutrients", "yield", "bioaccumulator", "salt-buildup", "root-zone" ], "stage": [ "ripen", "harvest" ], "systems": [ "any" ], "evidence": "myth", "evidence_name": "Myth", "level": "intermediate", "qa": [ "Should I flush my cannabis before harvest?", "Is flushing a myth?", "Does flushing improve taste or make white ash?", "Does flushing reduce yield?", "How long should I flush?", "Should I flush living soil?", "When is flushing actually useful?", "How do I flush salt build-up out of coco or soil?", "Does lower nitrogen at the end raise THC percentage?", "What should I do instead of flushing?", "Should I put my plants in darkness before harvest?", "How do I taper nitrogen before harvest?", "Why does tissue nitrogen drop in late flower?" ], "myths": [ "Flushing with plain water before harvest makes smoother, better-tasting buds" ], "related": [ "kb-nutrients-flushing", "kb-harvest-cure-trichome-ripeness", "kb-harvest-cure-drying", "kb-harvest-cure-curing-burping", "kb-nutrients-feed-by-stage", "kb-nutrients-nitrogen" ], "sources_count": 10, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-harvest-cure-trichome-ripeness", "title": "Trichome ripeness: clear, cloudy, amber, and what the evidence says", "category": "harvest-cure", "category_name": "Harvest and cure", "slug": "trichome-ripeness", "url": "https://genetixbay.com/knowledge/harvest-cure/trichome-ripeness.html", "markdown_url": "https://genetixbay.com/knowledge/harvest-cure/trichome-ripeness.md", "summary": "Trichome heads go from clear to cloudy (milky) to amber or brown as flowers mature; research confirms browning marks gland senescence and that trichomes on one bract mature unevenly and at genotype-specific rates. Cannabinoid concentration typically rises to a plateau and then falls as plants senesce. The popular claim that amber heads mean high CBN and couch-lock is a myth: CBN mainly forms by oxidation after harvest. A dark period before harvest is a myth too. Harvest when most heads are cloudy with some amber, and track it by date and lab tests for your cultivar.", "tags": [ "trichomes", "harvest-timing", "amber", "cloudy", "milky", "cbn", "ripeness", "loupe" ], "stage": [ "ripen", "harvest" ], "systems": [ "any" ], "evidence": "grower_practice", "evidence_name": "Grower practice", "level": "intermediate", "qa": [ "Should I harvest at cloudy or amber trichomes?", "When should I harvest based on trichomes?", "Does amber trichome mean more CBN?", "Do amber trichomes make a couchlock high?", "Should I put my plants in darkness before harvest?", "What percentage of amber trichomes should I harvest at?", "Should I look at trichomes on the sugar leaves or the calyx?", "Are pistil colours a good harvest indicator?" ], "myths": [ "24–72 hours of darkness before harvest boosts resin and THC", "Amber trichomes mean CBN and couch-lock" ], "related": [ "kb-basics-buyer-beware-label-claims", "kb-harvest-cure-flush-debate", "kb-harvest-cure-drying", "kb-harvest-cure-long-term-storage", "kb-environment-photoperiod-light-leaks", "kb-environment-flip-to-flower-transition" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-backcrossing-ibl-stabilisation", "title": "Backcrossing, IBLs and stabilisation", "category": "breeding", "category_name": "Breeding", "slug": "backcrossing-ibl-stabilisation", "url": "https://genetixbay.com/knowledge/breeding/backcrossing-ibl-stabilisation.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/backcrossing-ibl-stabilisation.md", "summary": "A backcross crosses offspring back to one parent (the recurrent parent) to recover that parent's genome while keeping a trait from the other: each backcross halves the donor's share (50%, 25%, 12.5%, 6.25%...). An IBL is a line inbred and selected over many generations until it breeds fairly true. 'Stable' should mean measured uniformity across a grow-out, not a generation count.", "tags": [ "backcross", "BX", "IBL", "inbred-line", "stabilisation", "recurrent-parent", "introgression", "cubing" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "breeder", "qa": [ "What is a backcross in cannabis breeding?", "What does BX1, BX2, BX3 mean?", "What is cubing?", "What is an IBL and how many generations does it take?", "How do I know if my line is stable?", "How do I add one trait to my favourite strain?" ], "myths": [], "related": [ "kb-breeding-f1-f2-f3-explained", "kb-breeding-s1-selfing", "kb-breeding-inbreeding-depression-hybrid-vigour", "kb-breeding-breeding-autoflowers", "kb-breeding-documenting-lineage-evidence" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-record-keeping-naming-ethics", "title": "Breeder record-keeping and naming ethics", "category": "breeding", "category_name": "Breeding", "slug": "record-keeping-naming-ethics", "url": "https://genetixbay.com/knowledge/breeding/record-keeping-naming-ethics.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/record-keeping-naming-ethics.md", "summary": "Keep a dated record of every plant, cross, batch and test, linked by permanent IDs, so any seed can be traced to its parents. Name lines honestly: a new, unique name for new genetics, the original name only for the original genetics, clear labels (F2, BX, S1, feminised), and never a famous name on something it isn't. Names are claims; records are the evidence. Sex stability is part of the ethics: cull herm-prone plants, never breed from them, and publish every batch's herm rate.", "tags": [ "records", "pedigree", "naming", "ethics", "cultivar-name", "GB-BAT", "GB-GEN", "honesty", "provenance" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "breeder", "qa": [ "What records should a cannabis breeder keep?", "How should I name my new strain?", "Can I use someone else's strain name?", "What should go on a seed pack label?", "How do I write a pedigree?", "Is it OK to rename a clone?", "Should breeders disclose hermaphrodite rates?", "Is it ethical to sell seed from a plant that hermed?" ], "myths": [], "related": [ "kb-diagnosis-hermaphrodites", "kb-breeding-s1-selfing", "kb-breeding-feminised-seed-sex-reversal", "kb-breeding-documenting-lineage-evidence", "kb-breeding-seed-germination-testing-qc", "kb-breeding-selection-pheno-hunting" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-breeders-vs-pollen-chuckers", "title": "Breeders vs pollen chuckers: what real cannabis breeding looks like", "category": "breeding", "category_name": "Breeding", "slug": "breeders-vs-pollen-chuckers", "url": "https://genetixbay.com/knowledge/breeding/breeders-vs-pollen-chuckers.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/breeders-vs-pollen-chuckers.md", "summary": "A breeder sets a goal, grows large populations, selects both females and males, progeny-tests the parents, stabilises the line over generations (F2s, backcrosses, IBLs), test-grows every batch and discloses its herm rate. A pollen chucker crosses two popular cuts, or selfs one, and sells the first-generation seed untested. Plant-breeding science explains why the difference shows up in your tent: crosses of heterozygous clones segregate, selecting only one sex halves progress, and intersex expression is heritable and responds to selection.", "tags": [ "breeding", "pollen-chucker", "selection", "males", "progeny-testing", "stabilisation", "ibl", "herm-rate", "heritability", "breeders-equation", "ethics", "f1", "s1" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "What is a pollen chucker?", "What's the difference between a breeder and a pollen chucker?", "Is crossing two clones breeding?", "Why do males matter in cannabis breeding?", "How many plants do you need to test a seed line?", "How many plants to prove a low herm rate?", "Why are some seed lines so inconsistent?", "How do I tell if a seed line was properly bred?", "What is progeny testing?" ], "myths": [ "Crossing two famous cuts makes a new strain", "Only the females matter in breeding", "A 10-plant test grow proves a line is herm-free" ], "related": [ "kb-breeding-record-keeping-naming-ethics", "kb-breeding-documenting-lineage-evidence", "kb-breeding-selection-pheno-hunting", "kb-breeding-backcrossing-ibl-stabilisation", "kb-breeding-s1-selfing", "kb-diagnosis-hermaphrodites" ], "sources_count": 14, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-breeding-autoflowers", "title": "Breeding autoflowers: getting the trait into a photoperiod line", "category": "breeding", "category_name": "Breeding", "slug": "breeding-autoflowers", "url": "https://genetixbay.com/knowledge/breeding/breeding-autoflowers.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/breeding-autoflowers.md", "summary": "Because autoflowering is recessive in mapped populations, a photo x auto F1 is all photoperiod. You recover autos in the F2 (about 1 in 4) or by backcrossing the F1 to the auto parent (about 1 in 2). To make an auto version of a photoperiod line, alternate crossing to the photo parent with a generation that reveals autos, or use a DNA marker to keep carriers.", "tags": [ "autoflower", "Autoflower1", "recessive", "backcross", "F2", "day-neutral", "marker-assisted" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "breeder", "qa": [ "How do I breed my own autoflower strain?", "Why are all my auto x photo seeds photoperiod?", "How many generations to make an autoflower version of a strain?", "Can I cross two autoflowers?", "How do I make sure my auto line is stable?", "Why are autoflowers less potent than photoperiods?", "Are autos better than photoperiods?" ], "myths": [], "related": [ "kb-breeding-breeders-vs-pollen-chuckers", "kb-breeding-quantitative-traits-heritability", "kb-germination-transplanting", "kb-training-lst", "kb-basics-photoperiod-vs-autoflower", "kb-breeding-backcrossing-ibl-stabilisation" ], "sources_count": 8, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-chemotype-inheritance", "title": "Chemotype inheritance: how THC and CBD synthase alleles pass on", "category": "breeding", "category_name": "Breeding", "slug": "chemotype-inheritance", "url": "https://genetixbay.com/knowledge/breeding/chemotype-inheritance.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/chemotype-inheritance.md", "summary": "Whether a plant is THC dominant, CBD dominant or mixed is controlled mainly by a single inheritance block carrying THCA synthase and CBDA synthase genes, which behaves close to codominant: THC x CBD gives mixed (type II) F1s and a 1:2:1 split in the F2. CBG-dominant and cannabinoid-free types come from non-functional synthase alleles. Total cannabinoid amount is a separate, quantitative trait.", "tags": [ "chemotype", "THCAS", "CBDAS", "THC", "CBD", "CBG", "codominant", "synthase", "chemotype-I", "chemotype-II", "chemotype-III" ], "stage": [ "flower" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "breeder", "qa": [ "If I cross a THC plant with a CBD plant what do I get?", "How is the THC to CBD ratio inherited?", "What are chemotypes I, II, III, IV and V?", "Can a 1:1 THC:CBD plant breed true?", "How are CBG-dominant plants made?", "Can I predict THC percentage from genetics?" ], "myths": [], "related": [ "kb-basics-buyer-beware-label-claims", "kb-breeding-mendelian-genetics-for-growers", "kb-breeding-quantitative-traits-heritability", "kb-breeding-genotyping-what-tests-prove", "kb-genetics-history-how-hybrid-strains-emerged" ], "sources_count": 8, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-clone-only-preservation", "title": "Clone-only cuts and how to preserve them", "category": "breeding", "category_name": "Breeding", "slug": "clone-only-preservation", "url": "https://genetixbay.com/knowledge/breeding/clone-only-preservation.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/clone-only-preservation.md", "summary": "A clone-only is one selected genotype kept alive by cuttings. It can be lost to pests, disease, hop latent viroid (HLVd) or accident, and it accumulates rare somatic mutations, which are not the same thing as a loss. Cuts from different parts of a plant can also behave differently (topophysis), so take them from consistent locations. Preserve it with clean, tested mothers in at least two locations, regular fresh cuttings, a tissue-culture backup where possible, and seed (S1s or crosses) as genetic insurance, not as a copy.", "tags": [ "clone-only", "cut", "mother-plant", "preservation", "HLVd", "viroid", "somatic-mutation", "topophysis", "cutting-position", "backup" ], "stage": [ "veg" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "advanced", "qa": [ "What is a clone-only strain?", "How do I keep a mother plant long-term?", "Do clones degrade over time (genetic drift)?", "Is clone decline real?", "What is hop latent viroid and how do I keep it out?", "How can I back up a clone?", "Is a clone-only from two different people the same plant?", "Why do clones from the same mother grow differently?", "Where on the mother should I take cuttings?" ], "myths": [], "related": [ "kb-breeding-tissue-culture-basics", "kb-breeding-s1-selfing", "kb-breeding-genotyping-what-tests-prove", "kb-basics-seed-types-regular-feminised-auto-clone", "kb-breeding-documenting-lineage-evidence", "kb-diseases-hop-latent-viroid-and-viruses" ], "sources_count": 7, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-pollen-collection-storage", "title": "Collecting and storing cannabis pollen", "category": "breeding", "category_name": "Breeding", "slug": "pollen-collection-storage", "url": "https://genetixbay.com/knowledge/breeding/pollen-collection-storage.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/pollen-collection-storage.md", "summary": "Collect pollen from freshly opened sacs in still, clean air, sieve it, dry it briefly, and use it within days, or mix it with a dry carrier (baked flour), seal it with desiccant and freeze it. Cannabis pollen loses viability within about a week in a fridge; one study kept it viable for at least four months by mixing it 1:10 with baked flour, vacuum-drying and storing in liquid nitrogen. Home freezer storage is grower practice and should be germination tested.", "tags": [ "pollen", "storage", "freezer", "flour", "desiccant", "viability", "cryopreservation" ], "stage": [ "flower" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "How do I collect cannabis pollen?", "How long does cannabis pollen last?", "Can I freeze cannabis pollen?", "Why mix pollen with flour?", "How do I test if my pollen is still viable?" ], "myths": [], "related": [ "kb-breeding-record-keeping-naming-ethics", "kb-breeding-s1-selfing", "kb-breeding-pollination-seed-production", "kb-breeding-feminised-seed-sex-reversal", "kb-breeding-clone-only-preservation" ], "sources_count": 3, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-elite-clone-gatekeeping", "title": "Elite clone-only gatekeeping: why the classics live in a few hands", "category": "breeding", "category_name": "Breeding", "slug": "elite-clone-gatekeeping", "url": "https://genetixbay.com/knowledge/breeding/elite-clone-gatekeeping.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/elite-clone-gatekeeping.md", "summary": "Many celebrated cultivars, from the Chem 91 and original OG Kush cuts to Pre-'98 Bubba Kush and old Skunk phenotypes, began as single plants and spread as cuttings through small circles. Published histories describe cuts passed only between friends, press reports put rare clone-only cuts at US$10,000 or more, and the classic Skunk aroma is described by veterans as gone from today's seed. The founder's view is that some holders keep cuts closed on purpose to control the gene pool. The public record documents the scarcity and the closed circles but can't show motive. A single garden is also a single point of failure: one HLVd infection or one bad summer can erase a cut. GenetixBay's answer is open preservation: GB-IDs, the Stud Book, preservation rewards and sharing in legal lanes.", "tags": [ "clone-only", "elite-cut", "cut-trading", "gatekeeping", "preservation", "skunk", "chemdog", "og-kush", "bubba-kush", "tissue-culture", "cryopreservation", "HLVd", "stud-book", "GB-ID" ], "stage": [ "veg" ], "systems": [ "any" ], "evidence": "grower_practice", "evidence_name": "Grower practice", "level": "intermediate", "qa": [ "What is an elite clone-only cut?", "Why are some strains clone-only?", "How much do elite cannabis clones cost?", "Is the original Skunk #1 lost?", "Where did the Chemdog and OG Kush cuts come from?", "Why won't people share rare cuts?", "How can rare clones be preserved?", "Can cannabis clones be frozen or stored in tissue culture?" ], "myths": [ "If it has the right name, it's the real cut" ], "related": [ "kb-breeding-clone-only-preservation", "kb-breeding-tissue-culture-basics", "kb-diseases-hop-latent-viroid-and-viruses", "kb-genetics-history-same-cut-a-thousand-names", "kb-genetics-history-why-everything-tastes-the-same", "kb-breeding-genotyping-what-tests-prove" ], "sources_count": 14, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-f1-f2-f3-explained", "title": "F1, F2, F3 explained: what filial generations really mean", "category": "breeding", "category_name": "Breeding", "slug": "f1-f2-f3-explained", "url": "https://genetixbay.com/knowledge/breeding/f1-f2-f3-explained.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/f1-f2-f3-explained.md", "summary": "An F1 is the first generation from two parents; it is uniform only if both parents were true-breeding (inbred). An F2 comes from crossing F1 siblings and shows the most variation. Each later generation of sib-mating with selection increases uniformity slowly. In cannabis, most 'F1 hybrids' are crosses of heterozygous clones, so they behave like segregating F2s.", "tags": [ "F1", "F2", "F3", "filial", "segregation", "uniformity", "homozygosity", "hybrid" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "intermediate", "qa": [ "What does F1 mean on a seed pack?", "Why are my F1 plants not uniform?", "Why are F2 seeds so variable?", "How many generations to make a stable strain?", "Is an F2 the same as an S1?" ], "myths": [], "related": [ "kb-breeding-mendelian-genetics-for-growers", "kb-breeding-backcrossing-ibl-stabilisation", "kb-breeding-s1-selfing", "kb-breeding-inbreeding-depression-hybrid-vigour", "kb-breeding-polyhybrids-vs-landraces" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-feminised-seed-sex-reversal", "title": "Feminised seed and sex reversal: methods, with safety notes", "category": "breeding", "category_name": "Breeding", "slug": "feminised-seed-sex-reversal", "url": "https://genetixbay.com/knowledge/breeding/feminised-seed-sex-reversal.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/feminised-seed-sex-reversal.md", "summary": "Feminised seed is made by forcing a genetic female to grow male flowers, then using that pollen on another (or the same) female. Silver ions block ethylene action; silver thiosulfate (STS) sprayed at about 3 mM silver was the most effective treatment in a controlled hemp study, and colloidal silver also works. Silver compounds are hazardous: wear gloves and eye protection, never consume treated plants, and dispose of waste as hazardous. Careless feminising (unproven donors, stress-herm pollen) is a main source of herm-prone seed; reverse only females proven stable over at least two runs.", "tags": [ "feminised", "sex-reversal", "silver-thiosulfate", "STS", "colloidal-silver", "reversed-female", "ethylene", "safety", "hermaphrodite", "breeding-ethics" ], "stage": [ "veg", "transition", "flower" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "breeder", "qa": [ "How are feminised seeds made?", "How do I make silver thiosulfate for reversing cannabis?", "Colloidal silver or STS for feminised seeds?", "When should I spray STS?", "Is reversed pollen safe? Can I smoke a reversed plant?", "Why do some feminised seeds turn out hermaphrodite?" ], "myths": [], "related": [ "kb-breeding-s1-selfing", "kb-breeding-pollination-seed-production", "kb-breeding-pollen-collection-storage", "kb-basics-sex-male-female-hermaphrodite", "kb-basics-seed-types-regular-feminised-auto-clone", "kb-diagnosis-hermaphrodites" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-genotyping-what-tests-prove", "title": "Genotyping: what a DNA test can and can't prove", "category": "breeding", "category_name": "Breeding", "slug": "genotyping-what-tests-prove", "url": "https://genetixbay.com/knowledge/breeding/genotyping-what-tests-prove.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/genotyping-what-tests-prove.md", "summary": "A DNA test can reliably show whether two samples are the same genotype, rule out a claimed parent (exclusion), support a parent-child relationship when both parents are sampled, predict sex and chemotype class from seedlings, and place a plant on a map of genetic groups. It cannot prove a 40-year-old pedigree from a name, measure THC %, tell you a plant's 'indica percentage', or guarantee how it will grow.", "tags": [ "genotyping", "DNA-test", "SNP", "microsatellite", "parentage", "fingerprint", "sex-test", "chemotype-marker", "L4" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "breeder", "qa": [ "Can a DNA test prove my strain's lineage?", "Can genetics tests tell if two clones are the same?", "What does a cannabis genotype report show?", "Can DNA tell me the THC percentage?", "Is a sativa/indica percentage from a DNA test real?", "What do I need for an L4 lineage confirmation?" ], "myths": [], "related": [ "kb-breeding-documenting-lineage-evidence", "kb-breeding-clone-only-preservation", "kb-breeding-chemotype-inheritance", "kb-genetics-history-why-strain-names-are-unreliable" ], "sources_count": 7, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-documenting-lineage-evidence", "title": "How to document lineage evidence (GB-ID evidence levels L0-L4)", "category": "breeding", "category_name": "Breeding", "slug": "documenting-lineage-evidence", "url": "https://genetixbay.com/knowledge/breeding/documenting-lineage-evidence.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/documenting-lineage-evidence.md", "summary": "On GenetixBay every parentage statement is a claim with an evidence level: L0 unverified, L1 community reported with a source, L2 breeder reported, L3 documented by an accepted GB-DOC, L4 lab-confirmed by a genomic report consistent with the parent-child relationship. Breeders raise the level by attaching dated, original evidence and, where possible, by recording crosses on the platform as they happen.", "tags": [ "lineage", "provenance", "evidence-levels", "GB-ID", "GB-DOC", "claims", "pedigree", "archivist", "disputes" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "breeder", "qa": [ "How do I prove the lineage of my strain?", "What are GenetixBay evidence levels?", "What documents count as lineage evidence?", "How do I get my cross to L3 or L4?", "What is a witnessed lineage?", "How are lineage disputes handled?" ], "myths": [], "related": [ "kb-breeding-record-keeping-naming-ethics", "kb-breeding-genotyping-what-tests-prove", "kb-genetics-history-why-strain-names-are-unreliable", "kb-genetics-history-how-hybrid-strains-emerged" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-inbreeding-depression-hybrid-vigour", "title": "Inbreeding depression and hybrid vigour", "category": "breeding", "category_name": "Breeding", "slug": "inbreeding-depression-hybrid-vigour", "url": "https://genetixbay.com/knowledge/breeding/inbreeding-depression-hybrid-vigour.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/inbreeding-depression-hybrid-vigour.md", "summary": "Inbreeding makes hidden harmful recessive alleles homozygous, so inbred plants often lose vigour, yield and fertility (inbreeding depression). Crossing unrelated lines masks those alleles and can push F1s above both parents (hybrid vigour, or heterosis). The vigour fades in the F2 because the masking breaks down as genes segregate.", "tags": [ "inbreeding-depression", "heterosis", "hybrid-vigour", "F1", "effective-population-size", "purging" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "breeder", "qa": [ "What is inbreeding depression in cannabis?", "Why are my F2 or S1 plants weaker?", "What is hybrid vigour?", "Why are F1 hybrids so vigorous?", "How do I avoid inbreeding depression when stabilising a line?", "Does hybrid vigour carry on into the next generation?" ], "myths": [], "related": [ "kb-breeding-s1-selfing", "kb-diagnosis-hermaphrodites", "kb-breeding-f1-f2-f3-explained", "kb-breeding-backcrossing-ibl-stabilisation", "kb-breeding-polyhybrids-vs-landraces", "kb-breeding-quantitative-traits-heritability" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-mendelian-genetics-for-growers", "title": "Mendelian genetics for growers, with Punnett squares", "category": "breeding", "category_name": "Breeding", "slug": "mendelian-genetics-for-growers", "url": "https://genetixbay.com/knowledge/breeding/mendelian-genetics-for-growers.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/mendelian-genetics-for-growers.md", "summary": "Traits controlled by one gene follow Mendel's rules: each parent passes one of its two alleles at random, so a cross of two heterozygotes gives a 1:2:1 genotype ratio and, for a dominant trait, a 3:1 look. In cannabis the clearest single-gene examples are autoflowering (recessive) and the THC/CBD chemotype switch (close to codominant).", "tags": [ "mendel", "punnett-square", "dominant", "recessive", "codominant", "segregation", "independent-assortment", "linkage" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "intermediate", "qa": [ "How do Punnett squares work for cannabis?", "What does 3:1 ratio mean?", "What is dominant and recessive in cannabis?", "How many plants do I need to find a recessive trait?", "Why don't my F2 ratios match the textbook?", "What is linkage?" ], "myths": [], "related": [ "kb-breeding-quantitative-traits-heritability", "kb-breeding-chemotype-inheritance", "kb-basics-photoperiod-vs-autoflower", "kb-breeding-f1-f2-f3-explained", "kb-breeding-selection-pheno-hunting" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-pollination-seed-production", "title": "Pollination and seed production, step by step", "category": "breeding", "category_name": "Breeding", "slug": "pollination-seed-production", "url": "https://genetixbay.com/knowledge/breeding/pollination-seed-production.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/pollination-seed-production.md", "summary": "Pollinate females about 2-4 weeks into flower when stigmas are white and receptive, using fresh or stored pollen applied with a brush or bag to marked branches; seeds mature in roughly 5-7 weeks. Isolation is everything: pollen travels on air, clothing and fans, so a planned cross needs a separate space or strict bagging, and every pollination gets a dated record.", "tags": [ "pollination", "seed-production", "isolation", "branch-pollination", "seed-maturity", "harvest-seed" ], "stage": [ "flower", "ripen", "harvest" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "When should I pollinate my cannabis plant?", "How long do cannabis seeds take to mature after pollination?", "How do I pollinate just one branch?", "How do I stop pollen from getting everywhere?", "How do I know seeds are ripe?", "How many seeds does one plant make?" ], "myths": [], "related": [ "kb-breeding-s1-selfing", "kb-breeding-pollen-collection-storage", "kb-breeding-feminised-seed-sex-reversal", "kb-breeding-seed-germination-testing-qc", "kb-breeding-record-keeping-naming-ethics", "kb-basics-sex-male-female-hermaphrodite" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-polyhybrids-vs-landraces", "title": "Polyhybrids vs landraces: what each gives a breeder", "category": "breeding", "category_name": "Breeding", "slug": "polyhybrids-vs-landraces", "url": "https://genetixbay.com/knowledge/breeding/polyhybrids-vs-landraces.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/polyhybrids-vs-landraces.md", "summary": "A landrace is a locally adapted, farmer-maintained population with a regional history; it is variable but coherent, and a reservoir of diversity. A polyhybrid is a modern line with many ancestors from different gene pools; it can be highly productive but is heterozygous and segregates unpredictably. Breeders use landraces as sources of new traits and polyhybrids as elite starting material.", "tags": [ "landrace", "polyhybrid", "heirloom", "genetic-diversity", "preservation", "open-pollinated" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "advanced", "qa": [ "What is a landrace strain?", "What is a polyhybrid?", "Are landraces more stable than hybrids?", "Why are my polyhybrid seeds so variable?", "How should a landrace be preserved?", "Is an heirloom the same as a landrace?" ], "myths": [], "related": [ "kb-genetics-history-landraces-of-the-world", "kb-genetics-history-how-hybrid-strains-emerged", "kb-breeding-f1-f2-f3-explained", "kb-breeding-inbreeding-depression-hybrid-vigour" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-quantitative-traits-heritability", "title": "Quantitative traits and heritability: why most good traits are hard to fix", "category": "breeding", "category_name": "Breeding", "slug": "quantitative-traits-heritability", "url": "https://genetixbay.com/knowledge/breeding/quantitative-traits-heritability.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/quantitative-traits-heritability.md", "summary": "Yield, potency, terpene totals, vigour and flowering time are controlled by many genes plus environment. Heritability (the share of variation due to genes in a given population and setting) predicts how much of a selected plant's advantage passes to its offspring: response = heritability x selection differential. Cannabinoid ratios are highly heritable; absolute THC % and yield much less so.", "tags": [ "quantitative-traits", "heritability", "polygenic", "genotype-by-environment", "breeders-equation", "selection-response" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "breeder", "qa": [ "What is heritability in plant breeding?", "Why don't the offspring of my best plant perform as well?", "Is THC percentage genetic or environmental?", "What is the breeder's equation?", "How do I reduce environmental noise in a pheno hunt?", "What is genotype by environment interaction?" ], "myths": [], "related": [ "kb-breeding-mendelian-genetics-for-growers", "kb-breeding-selection-pheno-hunting", "kb-breeding-chemotype-inheritance", "kb-breeding-inbreeding-depression-hybrid-vigour" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-s1-selfing", "title": "S1s and selfing: what happens when a plant pollinates itself", "category": "breeding", "category_name": "Breeding", "slug": "s1-selfing", "url": "https://genetixbay.com/knowledge/breeding/s1-selfing.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/s1-selfing.md", "summary": "An S1 is seed from a plant pollinated by its own pollen, usually by reversing one female clone or branch. S1s are feminised, and they are not copies of the parent: each S1 seed is a new genotype. Selfing halves heterozygosity per generation, reveals hidden recessives (good and bad), and is a fast way to test what a clone carries. Done carelessly, especially S1 on S1 from plants that herm, it is one of the main ways herm-prone lines are made; only self proven-stable females and cull every intersex offspring.", "tags": [ "S1", "selfing", "self-pollination", "recessive", "homozygosity", "feminised", "inbreeding", "hermaphrodite", "breeding-ethics" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "established", "evidence_name": "Established", "level": "breeder", "qa": [ "What is an S1 seed?", "Is an S1 a copy of the mother plant?", "Are S1 seeds feminised?", "Why are my S1s weaker than the clone?", "What is an S2?", "Should I make S1s of my keeper?", "Do S1 seeds turn hermaphrodite?" ], "myths": [], "related": [ "kb-breeding-feminised-seed-sex-reversal", "kb-breeding-f1-f2-f3-explained", "kb-breeding-inbreeding-depression-hybrid-vigour", "kb-breeding-clone-only-preservation", "kb-basics-sex-male-female-hermaphrodite", "kb-diagnosis-hermaphrodites" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-seed-germination-testing-qc", "title": "Seed germination testing and quality control for breeders", "category": "breeding", "category_name": "Breeding", "slug": "seed-germination-testing-qc", "url": "https://genetixbay.com/knowledge/breeding/seed-germination-testing-qc.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/seed-germination-testing-qc.md", "summary": "Before seed leaves your hands, test it: germinate a random sample of at least 100 seeds (400 in four replicates is the lab standard) and count normal seedlings, not just cracked seeds. Report the result with the date on the batch record. Store seed cool and dry; one study recommended about 5 °C to keep germination for years.", "tags": [ "germination-test", "seed-quality", "viability", "tetrazolium", "seed-storage", "QC", "batch" ], "stage": [ "seedling" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "breeder", "qa": [ "How do I test cannabis seed germination rate?", "What is a good germination rate for cannabis seeds?", "How many seeds should I test?", "How should I store cannabis seeds?", "How long do cannabis seeds stay viable?", "What is a tetrazolium test?" ], "myths": [], "related": [ "kb-breeding-pollination-seed-production", "kb-breeding-record-keeping-naming-ethics", "kb-breeding-documenting-lineage-evidence", "kb-basics-seed-types-regular-feminised-auto-clone", "kb-germination-seed-viability-storage" ], "sources_count": 6, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-selection-pheno-hunting", "title": "Selection and pheno hunting: sample sizes and scoring rubrics", "category": "breeding", "category_name": "Breeding", "slug": "selection-pheno-hunting", "url": "https://genetixbay.com/knowledge/breeding/selection-pheno-hunting.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/selection-pheno-hunting.md", "summary": "A pheno hunt is a selection experiment: grow enough seeds to have a real chance of finding what you want, clone every candidate before flowering, score each plant on a fixed weighted rubric, and re-grow the top few as clones before you call a keeper. The plants needed follow 1 - (1 - p)^n: a 1-in-10 type needs 29 plants for a 95% chance of seeing at least one. Sex stability is a gate: any plant that herms is culled, whatever else it scores.", "tags": [ "pheno-hunting", "selection", "sample-size", "scoring", "rubric", "keeper", "clones", "GB-IND", "hermaphrodite", "sex-stability" ], "stage": [ "veg", "flower", "harvest", "cure" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "advanced", "qa": [ "How many seeds should I pop for a pheno hunt?", "How do I pick a keeper?", "What should I score in a pheno hunt?", "Should I clone before flowering?", "How many times should I run a cut before deciding?" ], "myths": [], "related": [ "kb-diagnosis-hermaphrodites", "kb-breeding-quantitative-traits-heritability", "kb-breeding-mendelian-genetics-for-growers", "kb-breeding-f1-f2-f3-explained", "kb-breeding-record-keeping-naming-ethics", "kb-breeding-clone-only-preservation" ], "sources_count": 5, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-breeding-tissue-culture-basics", "title": "Tissue culture basics for cannabis growers and breeders", "category": "breeding", "category_name": "Breeding", "slug": "tissue-culture-basics", "url": "https://genetixbay.com/knowledge/breeding/tissue-culture-basics.html", "markdown_url": "https://genetixbay.com/knowledge/breeding/tissue-culture-basics.md", "summary": "Tissue culture grows small pieces of a plant (usually nodes or shoot tips) on a sterile gel medium, giving clean, compact, long-lived backups of clones and a route to cleaning up infected stock. Cannabis tissue culture works but is genotype dependent and poorly replicated in the literature; contamination control is the main skill.", "tags": [ "tissue-culture", "micropropagation", "meristem", "aseptic", "sterile", "DKW", "MS-medium", "acclimatisation" ], "stage": [ "veg" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "advanced", "qa": [ "What is cannabis tissue culture?", "Can I do tissue culture at home?", "Does tissue culture remove viroids?", "What medium is used for cannabis tissue culture?", "How long can a cannabis clone be kept in tissue culture?" ], "myths": [], "related": [ "kb-breeding-clone-only-preservation", "kb-breeding-genotyping-what-tests-prove", "kb-basics-seed-types-regular-feminised-auto-clone", "kb-diseases-hop-latent-viroid-and-viruses" ], "sources_count": 4, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-genetics-history-craft-vs-industrial-cannabis", "title": "Craft vs industrial cannabis: did legalisation's commercial model hurt quality?", "category": "genetics-history", "category_name": "Genetics history", "slug": "craft-vs-industrial-cannabis", "url": "https://genetixbay.com/knowledge/genetics-history/craft-vs-industrial-cannabis.html", "markdown_url": "https://genetixbay.com/knowledge/genetics-history/craft-vs-industrial-cannabis.md", "summary": "The founder's opinion is that legalisation's commercial model hurt quality: small, careful growers were priced out by large facilities, and product is now grown to a price. The evidence supports parts of that. Wholesale prices fell by roughly 75-80 %, Oregon's flower is at its lowest price since legalisation, Washington lost about a third of its producer businesses from 2017 to 2023, California's licensed canopy is dominated by a few large farms, Canadian excise duty can take 30 % or more of a producer's gross revenue, and regulators have recalled legal product for mould and pesticides. But no data show the grey market was cleaner, and Health Canada's own testing found illegal flower far dirtier than legal flower. Craft vs industrial is the real fault line. Growing your own, where legal, is the surest way to control quality.", "tags": [ "craft", "legalisation", "consolidation", "small-growers", "recalls", "contamination", "pesticides", "aspergillus", "irradiation", "licensing", "excise", "price-collapse", "appellations", "grow-your-own" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "contested", "evidence_name": "Contested", "level": "intermediate", "qa": [ "Did legalisation make weed worse?", "Is craft cannabis better than commercial cannabis?", "Why are small cannabis farms going out of business?", "Is legal cannabis contaminated?", "Was grey-market weed better than legal weed?", "Why is legal weed so cheap now?", "How much does excise duty cost Canadian cannabis growers?", "What are cannabis appellations of origin?", "Is legal cannabis irradiated?" ], "myths": [ "Legal cannabis is clean because it's tested" ], "related": [ "kb-harvest-cure-irradiated-cannabis", "kb-genetics-history-why-everything-tastes-the-same", "kb-genetics-history-patents-and-the-gene-pool", "kb-basics-buyer-beware-label-claims", "kb-diseases-botrytis-bud-rot", "kb-basics-first-grow-guide" ], "sources_count": 18, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-genetics-history-how-hybrid-strains-emerged", "title": "How hybrid 'strains' emerged", "category": "genetics-history", "category_name": "Genetics history", "slug": "how-hybrid-strains-emerged", "url": "https://genetixbay.com/knowledge/genetics-history/how-hybrid-strains-emerged.html", "markdown_url": "https://genetixbay.com/knowledge/genetics-history/how-hybrid-strains-emerged.md", "summary": "Modern drug-type cannabis is mostly a mix of South Asian-derived long-flowering types and Central Asian (Afghan) hashish types, crossed from the 1970s onwards in North America, then distributed by Dutch seed companies from the mid-1980s, and multiplied into thousands of names in clone-driven and legal markets since the 1990s. The broad story is supported by genetics; most specific pedigrees are oral claims with conflicting versions.", "tags": [ "history", "hybrids", "1970s", "Afghani", "Skunk", "Haze", "Northern-Lights", "seed-banks", "Netherlands", "Kush", "CBD-introgression" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "contested", "evidence_name": "Contested", "level": "intermediate", "qa": [ "Where did modern cannabis strains come from?", "When did indica and sativa get crossed?", "What is the history of Skunk #1?", "Why did Dutch seed banks matter?", "Where did CBD strains come from?", "Are famous strain pedigrees true?" ], "myths": [], "related": [ "kb-genetics-history-landraces-of-the-world", "kb-genetics-history-why-strain-names-are-unreliable", "kb-breeding-polyhybrids-vs-landraces", "kb-breeding-documenting-lineage-evidence" ], "sources_count": 8, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-genetics-history-indica-sativa-ruderalis", "title": "Indica, sativa and ruderalis: what the names really mean", "category": "genetics-history", "category_name": "Genetics history", "slug": "indica-sativa-ruderalis", "url": "https://genetixbay.com/knowledge/genetics-history/indica-sativa-ruderalis.html", "markdown_url": "https://genetixbay.com/knowledge/genetics-history/indica-sativa-ruderalis.md", "summary": "Cannabis is one species, Cannabis sativa L., showing different phenotypes. Nearly everything grown today is a hybrid, with a few outlier landraces. Distinct groups, ruderalis included, may have existed long ago, but not today. As a guide to effects or species, indica vs sativa is nonsense: genetic and chemical studies show the labels don't match ancestry or predict chemistry. At most they describe plant shape: leaflet width, structure and flowering time.", "tags": [ "indica", "sativa", "ruderalis", "taxonomy", "species", "nomenclature", "Lamarck", "Linnaeus", "chemotype" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Is indica a different species from sativa?", "What is Cannabis ruderalis?", "Why do botanists say sativa and indica are mixed up?", "What is the difference between indica and sativa genetically?", "Does indica mean sedating?", "Does sativa give you energy?", "Is everything a hybrid now?" ], "myths": [ "Indica = couch, sativa = energy, and they're different species" ], "related": [ "kb-basics-buyer-beware-label-claims", "kb-genetics-history-landraces-of-the-world", "kb-genetics-history-why-strain-names-are-unreliable", "kb-basics-photoperiod-vs-autoflower", "kb-basics-cannabis-plant-biology" ], "sources_count": 8, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-genetics-history-landrace-hunting-and-biopiracy", "title": "Landrace hunting or biopiracy? Benefit-sharing, consent and cannabis", "category": "genetics-history", "category_name": "Genetics history", "slug": "landrace-hunting-and-biopiracy", "url": "https://genetixbay.com/knowledge/genetics-history/landrace-hunting-and-biopiracy.html", "markdown_url": "https://genetixbay.com/knowledge/genetics-history/landrace-hunting-and-biopiracy.md", "summary": "International law says a country owns rights over its genetic resources: under the Convention on Biological Diversity (1992) and the Nagoya Protocol (in force 2014), anyone taking plant material for breeding or research needs prior informed consent and mutually agreed terms, including benefit-sharing. Cannabis falls through the cracks: it isn't in the Plant Treaty's crop list, it's still a Schedule I drug under the 1961 Single Convention, most seed was collected before these rules existed, and the US and Canada aren't Nagoya parties. Turmeric, neem, hoodia and rooibos show what credit and compensation look like when they're taken seriously. GenetixBay's position: credit the source community, collect only legally, share seed back, and pay where benefits flow.", "tags": [ "landraces", "biopiracy", "benefit-sharing", "nagoya-protocol", "cbd", "prior-informed-consent", "traditional-knowledge", "plant-treaty", "dsi", "cali-fund", "credit", "preservation" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "What is biopiracy in cannabis?", "Is collecting landrace seed biopiracy?", "Does the Nagoya Protocol apply to cannabis?", "What is prior informed consent and benefit-sharing?", "Is Canada or the US a party to the Nagoya Protocol?", "Is cannabis covered by the Plant Treaty (ITPGRFA)?", "What is the Cali Fund?", "How should landrace seed be collected ethically?", "Should source communities be paid for landrace genetics?" ], "myths": [], "related": [ "kb-genetics-history-landraces-of-the-world", "kb-genetics-history-patents-and-the-gene-pool", "kb-genetics-history-why-everything-tastes-the-same", "kb-genetics-history-same-cut-a-thousand-names", "kb-breeding-documenting-lineage-evidence", "kb-breeding-polyhybrids-vs-landraces" ], "sources_count": 17, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-genetics-history-landraces-of-the-world", "title": "Landraces of the world: an overview", "category": "genetics-history", "category_name": "Genetics history", "slug": "landraces-of-the-world", "url": "https://genetixbay.com/knowledge/genetics-history/landraces-of-the-world.html", "markdown_url": "https://genetixbay.com/knowledge/genetics-history/landraces-of-the-world.md", "summary": "Drug-type cannabis landraces developed across South and Central Asia and were carried to Africa, the Middle East and the Americas, where local farmers adapted them over centuries. Genomic work points to an Asian origin of domestication (exact region contested). Many traditional landraces are now endangered by hybrid replacement, and most 'landrace' seed in commerce is better described as heirloom: collected at some point, then maintained elsewhere. Every origin story here is a claim; this article labels the evidence.", "tags": [ "landrace", "heritage", "Afghanistan", "Hindu-Kush", "India", "Thailand", "Colombia", "Mexico", "Jamaica", "Africa", "domestication", "conservation" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "What are the main cannabis landraces?", "Where did cannabis originate?", "What is an Afghani landrace?", "Are landraces still pure?", "Which landraces are sativa and which are indica?", "Are landrace seeds sold online real landraces?" ], "myths": [], "related": [ "kb-genetics-history-old-cannabis-was-not-weak", "kb-genetics-history-why-everything-tastes-the-same", "kb-genetics-history-patents-and-the-gene-pool", "kb-breeding-polyhybrids-vs-landraces", "kb-genetics-history-how-hybrid-strains-emerged", "kb-genetics-history-indica-sativa-ruderalis" ], "sources_count": 11, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-genetics-history-old-cannabis-was-not-weak", "title": "Old cannabis wasn't weak: the \"so much stronger than 20 years ago\" myth", "category": "genetics-history", "category_name": "Genetics history", "slug": "old-cannabis-was-not-weak", "url": "https://genetixbay.com/knowledge/genetics-history/old-cannabis-was-not-weak.html", "markdown_url": "https://genetixbay.com/knowledge/genetics-history/old-cannabis-was-not-weak.md", "summary": "\"Cannabis is far stronger than it used to be\" is false as a claim about the plant's genetics. Famous hashish, charas and sinsemilla traditions are centuries old and impossible with 5 % plants, and old seed grown well today still tests high. The 'weak old weed' numbers come from seized samples: mostly cheap compressed export brick of leaf, seed and stem, often stored for years before testing, measured with changing methods. The best of what source regions grew was rarely exported. What changed is the market and growing technique: fresh, seedless, indoor flower.", "tags": [ "potency", "history", "landraces", "hashish", "charas", "sinsemilla", "ganja", "kilobrick", "potency-monitoring", "thc-trends", "heirloom-seed", "export-market" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "myth", "evidence_name": "Myth", "level": "beginner", "qa": [ "Is weed stronger now than in the 1970s?", "Was old cannabis really only 3–5 % THC?", "Why do studies say cannabis potency has increased?", "Are landrace strains weak?", "How strong was traditional hashish or charas?", "Is today's cannabis a different plant from what my parents smoked?", "What was Mexican brick weed?", "Why wasn't good sinsemilla exported in the 1970s?" ], "myths": [ "Cannabis is much stronger than it was 20 (or 50) years ago" ], "related": [ "kb-genetics-history-landraces-of-the-world", "kb-genetics-history-how-hybrid-strains-emerged", "kb-genetics-history-why-everything-tastes-the-same", "kb-basics-buyer-beware-label-claims", "kb-harvest-cure-long-term-storage", "kb-genetics-history-indica-sativa-ruderalis" ], "sources_count": 23, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-genetics-history-patents-and-the-gene-pool", "title": "Patents and the gene pool: who can own a cannabis plant?", "category": "genetics-history", "category_name": "Genetics history", "slug": "patents-and-the-gene-pool", "url": "https://genetixbay.com/knowledge/genetics-history/patents-and-the-gene-pool.html", "markdown_url": "https://genetixbay.com/knowledge/genetics-history/patents-and-the-gene-pool.md", "summary": "Cannabis can be protected by US utility patents (covering plants, traits, extracts and methods), plant patents (for asexually reproduced varieties) and plant variety protection certificates (for seed-propagated hemp, since 2019), plus plant breeders' rights in Canada and the EU. Grants are public record. Legal commentators worry that thin prior art and broad claims could fence off parts of a shared gene pool. The open responses are public, dated documentation: prior-art databases, open-source seed pledges and genotype registries. GenetixBay's answer is preservation, GB-ID documentation and open sharing.", "tags": [ "patents", "plant-patent", "utility-patent", "pvp", "plant-breeders-rights", "prior-art", "open-source-seed", "defensive-publication", "preservation", "commons" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Can you patent a cannabis strain?", "Are there cannabis patents?", "What is a plant patent vs a utility patent?", "Can a patent stop me growing my own seeds?", "What is prior art for cannabis?", "How do I protect a landrace or heirloom from being patented?" ], "myths": [], "related": [ "kb-genetics-history-landraces-of-the-world", "kb-genetics-history-why-everything-tastes-the-same", "kb-breeding-documenting-lineage-evidence", "kb-breeding-record-keeping-naming-ethics", "kb-breeding-genotyping-what-tests-prove", "kb-breeding-clone-only-preservation" ], "sources_count": 11, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-genetics-history-same-cut-a-thousand-names", "title": "Same cut, a thousand names: renaming, relabelling and the shrinking gene pool", "category": "genetics-history", "category_name": "Genetics history", "slug": "same-cut-a-thousand-names", "url": "https://genetixbay.com/knowledge/genetics-history/same-cut-a-thousand-names.html", "markdown_url": "https://genetixbay.com/knowledge/genetics-history/same-cut-a-thousand-names.md", "summary": "Renaming clones, relabelling cuts and reusing famous names make the market look far more diverse than it is. Genetic studies find the same plant sold under different names and different plants sold under one name: in one study 35 % of comparisons put a sample closer to a differently named sample than to its namesakes, and in Nevada 637 recorded names (396 after cleaning) covered three chemical profiles. Hidden sameness makes breeders cross near-identical material while believing they're adding diversity. GenetixBay's answer is the GB-ID: a permanent record tied to the plant, its source and its evidence, not to its name.", "tags": [ "strain-names", "renaming", "relabelling", "clones", "cuts", "mislabelling", "genotyping", "diversity", "gene-pool", "gb-id" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Are different strain names really different plants?", "Why do so many strains seem to be the same plant?", "Do growers rename clones?", "Is the same cut sold under different names?", "What studies show cannabis strains are mislabelled?", "How does renaming strains hurt cannabis genetic diversity?", "How can I tell if two strains are the same cut?", "What is a GB-ID?" ], "myths": [ "Different names mean different plants", "A new name means new genetics", "If it has the famous name, it's the famous cut" ], "related": [ "kb-genetics-history-why-everything-tastes-the-same", "kb-genetics-history-why-strain-names-are-unreliable", "kb-breeding-record-keeping-naming-ethics", "kb-breeding-genotyping-what-tests-prove", "kb-breeding-documenting-lineage-evidence", "kb-breeding-clone-only-preservation" ], "sources_count": 11, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-genetics-history-why-everything-tastes-the-same", "title": "Why everything tastes the same: the evidence that commercial cannabis is converging", "category": "genetics-history", "category_name": "Genetics history", "slug": "why-everything-tastes-the-same", "url": "https://genetixbay.com/knowledge/genetics-history/why-everything-tastes-the-same.html", "markdown_url": "https://genetixbay.com/knowledge/genetics-history/why-everything-tastes-the-same.md", "summary": "Growers keep saying modern weed all tastes the same, and the data back them up. A study of nearly 90,000 US lab results found THC-dominant flower falling into just three terpene groups, two of which held about 87 % of samples. Strain names and indica/sativa labels promise far more variety than the chemistry shows, traditional landraces in their home regions are being replaced by introduced hybrids, and retail prices rise with THC rather than aroma. GenetixBay's answer is preservation, documentation with GB-IDs, and open sharing of distinctive lines.", "tags": [ "terpenes", "chemotype", "chemovar", "diversity", "convergence", "landraces", "introgression", "genetic-erosion", "thc-selection", "preservation" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "intermediate", "qa": [ "Why does all modern weed taste the same?", "Are strains losing their diversity?", "What are the main terpene profiles in cannabis?", "Are landrace strains disappearing?", "Why does the market breed for THC instead of flavour?", "How can I find cannabis with a different terpene profile?", "What makes cannabis smell like gas?", "Why is every new strain gas or candy?", "Are the classic strains disappearing?" ], "myths": [], "related": [ "kb-genetics-history-same-cut-a-thousand-names", "kb-genetics-history-landraces-of-the-world", "kb-genetics-history-old-cannabis-was-not-weak", "kb-genetics-history-why-strain-names-are-unreliable", "kb-genetics-history-patents-and-the-gene-pool", "kb-genetics-history-indica-sativa-ruderalis" ], "sources_count": 14, "reviewed": "draft", "updated": "2026-10-31" }, { "id": "kb-genetics-history-why-strain-names-are-unreliable", "title": "Why strain names are unreliable: what genetic studies show", "category": "genetics-history", "category_name": "Genetics history", "slug": "why-strain-names-are-unreliable", "url": "https://genetixbay.com/knowledge/genetics-history/why-strain-names-are-unreliable.html", "markdown_url": "https://genetixbay.com/knowledge/genetics-history/why-strain-names-are-unreliable.md", "summary": "Several genetic and chemical studies of retail cannabis show that the same strain name often hides different genotypes, that 'indica' and 'sativa' labels don't match genome-wide ancestry, and that potency labels vary by lab. Some names are reasonably consistent, many are not. A name is a claim; a documented source, a GB-ID with evidence and, ultimately, DNA are the evidence.", "tags": [ "strain-names", "mislabelling", "genetics", "indica", "sativa", "chemotype", "terpenes", "consistency", "studies" ], "stage": [ "any" ], "systems": [ "any" ], "evidence": "supported", "evidence_name": "Supported", "level": "beginner", "qa": [ "Are cannabis strain names accurate?", "Is my Blue Dream the same as someone else's?", "Do indica and sativa labels mean anything?", "Why does the same strain test differently?", "What studies show strain names are unreliable?", "How can I trust a strain name?" ], "myths": [ "A strain name tells you what genetics you're getting" ], "related": [ "kb-basics-buyer-beware-label-claims", "kb-genetics-history-how-hybrid-strains-emerged", "kb-genetics-history-indica-sativa-ruderalis", "kb-breeding-genotyping-what-tests-prove", "kb-breeding-documenting-lineage-evidence", "kb-breeding-record-keeping-naming-ethics" ], "sources_count": 7, "reviewed": "draft", "updated": "2026-10-31" } ] }