# GenetixBay > GenetixBay is a cannabis genetics and grow-science community (est. 2009, relaunching). Its Knowledge Base is a citation-backed reference on growing and breeding cannabis, written in the voice of Professor Greenleaf: the answer first, numbers with units and ranges, and an evidence label on every claim (Established, Supported, Grower practice, Contested, Myth). How to use this content: - Every article has a clean Markdown twin (the .md links below), a canonical HTML page with JSON-LD, and an entry in the JSON index: https://genetixbay.com/knowledge/api/index.json - The full text of every article, with its sources, is in one file: https://genetixbay.com/llms-full.txt - Front matter fields: category, stage (seedling…cure), systems (soil, coco, dwc…), evidence, level, review status and last-updated date. Prefer articles marked "Expert reviewed"; drafts are labelled. - Licence: article text is CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/). Attribute "GenetixBay Knowledge Base (genetixbay.com/knowledge)" and link to the article. - Safety: nothing here is medical or legal advice. Home-grow law varies by jurisdiction; check local rules. ## Knowledge Base - [Knowledge Base index](https://genetixbay.com/knowledge/): 146 articles by category - [JSON index](https://genetixbay.com/knowledge/api/index.json): metadata and summaries for every article - [Mythbusters](https://genetixbay.com/knowledge/mythbusters.md): popular grow myths with verdicts, and the open GenetixBay trials ## Basics Plant biology, life cycle, photoperiod vs auto, sex, first grows. - [Buyer beware: potency labels, strain names and other claims that don't hold up](https://genetixbay.com/knowledge/basics/buyer-beware-label-claims.md): 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'. (Supported) - [Cannabis growing and breeding glossary](https://genetixbay.com/knowledge/basics/glossary.md): Plain-language definitions of the growing, botany and breeding terms used across GenetixBay, with notes where the popular meaning differs from the scientific one. (Established) - [Cannabis plant biology: the parts and what they do](https://genetixbay.com/knowledge/basics/cannabis-plant-biology.md): 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. (Established) - [Male, female and hermaphrodite cannabis: how sex works](https://genetixbay.com/knowledge/basics/sex-male-female-hermaphrodite.md): 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. (Established) - [Photoperiod vs autoflower, and how autoflowering is inherited](https://genetixbay.com/knowledge/basics/photoperiod-vs-autoflower.md): 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. (Supported) - [Regular, feminised, autoflower or clone: choosing your starting material](https://genetixbay.com/knowledge/basics/seed-types-regular-feminised-auto-clone.md): 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. (Supported) - [The cannabis life cycle, stage by stage](https://genetixbay.com/knowledge/basics/life-cycle.md): 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. (Established) - [Your first grow: a plan from seed to jar](https://genetixbay.com/knowledge/basics/first-grow-guide.md): 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. (Supported) ## Germination Seed viability, germination, seedlings, damping-off, transplanting. - [Damping-off: why seedlings collapse at the soil line](https://genetixbay.com/knowledge/germination/damping-off.md): 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. (Established) - [Germination methods compared: soak, paper towel, plugs, direct sow](https://genetixbay.com/knowledge/germination/germination-methods.md): 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. (Supported) - [Seed viability and storage: keeping cannabis seeds alive](https://genetixbay.com/knowledge/germination/seed-viability-storage.md): 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. (Supported) - [Seedling care: the first three weeks](https://genetixbay.com/knowledge/germination/seedling-care.md): 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. (Supported) - [Transplanting: when, into what, and avoiding transplant shock](https://genetixbay.com/knowledge/germination/transplanting.md): 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. (Grower practice) ## Environment Temperature, humidity, VPD, airflow, CO₂ and light. - [Airflow: air exchange, canopy air speed and fan placement](https://genetixbay.com/knowledge/environment/airflow.md): 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. (Supported) - [CO₂ enrichment: when it pays, how much, and how to stay safe](https://genetixbay.com/knowledge/environment/co2-enrichment.md): 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. (Supported) - [Heat and light stress: taco leaves, bleaching and foxtails](https://genetixbay.com/knowledge/environment/heat-light-stress.md): 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. (Supported) - [Humidity by stage: RH targets from clone to cure](https://genetixbay.com/knowledge/environment/humidity-by-stage.md): 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. (Supported) - [Light spectrum: blue, red, far-red and UV, what's real](https://genetixbay.com/knowledge/environment/light-spectrum.md): 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. (Contested) - [Photoperiod and light leaks: 18/6, 12/12 and the dark period](https://genetixbay.com/knowledge/environment/photoperiod-light-leaks.md): 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. (Supported) - [PPFD and DLI by stage, with the evidence](https://genetixbay.com/knowledge/environment/ppfd-dli-by-stage.md): 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. (Supported) - [Temperature by stage: day, night and root-zone targets](https://genetixbay.com/knowledge/environment/temperature-by-stage.md): 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). (Supported) - [The flip isn't day 1 of flower: the 10–14 day transition and how to count it](https://genetixbay.com/knowledge/environment/flip-to-flower-transition.md): 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. (Supported) - [VPD explained: vapour pressure deficit for cannabis growers](https://genetixbay.com/knowledge/environment/vpd-explained.md): 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. (Supported) ## Nutrients Every element, deficiencies and toxicities, feed schedules, recipes. - ["Bloom boosters" for cannabis: what's real and what's marketing](https://genetixbay.com/knowledge/nutrients/bloom-boosters.md): 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. (Supported) - [Boron (B) in cannabis: distorted tips, dying roots and a narrow safe window](https://genetixbay.com/knowledge/nutrients/boron.md): 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. (Supported) - [Building a cannabis feed by stage: ppm targets per element and how to hit them](https://genetixbay.com/knowledge/nutrients/feed-by-stage.md): 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. (Supported) - [Cal-Mag: what it is, when you need it and when you don't](https://genetixbay.com/knowledge/nutrients/cal-mag.md): 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. (Supported) - [Calcium (Ca) in cannabis: deficiency, transport, targets and sources](https://genetixbay.com/knowledge/nutrients/calcium.md): 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. (Supported) - [Chlorine and chloride (Cl) in cannabis: a micronutrient you never need to add](https://genetixbay.com/knowledge/nutrients/chlorine.md): 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). (Supported) - [Copper (Cu) in cannabis: limp, distorted new growth and root-burning excess](https://genetixbay.com/knowledge/nutrients/copper.md): 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. (Supported) - [Flushing before harvest: myth (summary)](https://genetixbay.com/knowledge/nutrients/flushing.md): 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. (Myth) - [Hydroponic salts explained: what each fertiliser salt supplies](https://genetixbay.com/knowledge/nutrients/hydroponic-salts.md): 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. (Established) - [Iron (Fe) in cannabis: yellow new growth, chelates and pH](https://genetixbay.com/knowledge/nutrients/iron.md): 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. (Supported) - [Magnesium (Mg) in cannabis: interveinal yellowing, targets and the K-Ca competition](https://genetixbay.com/knowledge/nutrients/magnesium.md): 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. (Supported) - [Manganese (Mn) in cannabis: netted chlorosis, low-pH toxicity and the iron balance](https://genetixbay.com/knowledge/nutrients/manganese.md): 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. (Supported) - [Mobile vs immobile nutrients: reading old vs new leaves](https://genetixbay.com/knowledge/nutrients/mobile-vs-immobile-nutrients.md): 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. (Established) - [Molybdenum (Mo) in cannabis: the trace element nitrate depends on](https://genetixbay.com/knowledge/nutrients/molybdenum.md): 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. (Supported) - [Nickel (Ni) in cannabis: essential, needed in traces, almost never worth adding](https://genetixbay.com/knowledge/nutrients/nickel.md): 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. (Supported) - [Nitrogen (N) in cannabis: nitrate vs ammonium, deficiency, toxicity and targets](https://genetixbay.com/knowledge/nutrients/nitrogen.md): 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. (Supported) - [Nutrient antagonism and Mulder's chart: what the evidence actually says](https://genetixbay.com/knowledge/nutrients/nutrient-antagonism.md): 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. (Supported) - [Organic vs mineral nutrition for cannabis: what the trials show](https://genetixbay.com/knowledge/nutrients/organic-vs-mineral.md): 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. (Supported) - [Per-element feeding tricks: what growers adjust, stage by stage](https://genetixbay.com/knowledge/nutrients/per-element-tricks.md): 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. (Grower practice) - [Phosphorus (P) in cannabis: what it does, deficiency, excess and how much is enough](https://genetixbay.com/knowledge/nutrients/phosphorus.md): 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. (Supported) - [Potassium (K) in cannabis: role, deficiency, excess and K-Ca-Mg balance](https://genetixbay.com/knowledge/nutrients/potassium.md): 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. (Supported) - [Silicon (Si) for cannabis: beneficial, not essential, and how to dose it](https://genetixbay.com/knowledge/nutrients/silicon.md): 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. (Contested) - [Sodium (Na) and cannabis: a salt to keep low, not a nutrient to add](https://genetixbay.com/knowledge/nutrients/sodium.md): 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. (Supported) - [Sulfur (S) in cannabis: role, deficiency, targets and sulfate sources](https://genetixbay.com/knowledge/nutrients/sulfur.md): 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. (Supported) - [Zinc (Zn) in cannabis: small leaves, margin burn and the phosphorus link](https://genetixbay.com/knowledge/nutrients/zinc.md): 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. (Supported) ## pH and EC pH, EC and ppm scales, water quality, runoff, drift. - [Buffering coco coir: why it matters and how to do it](https://genetixbay.com/knowledge/ph-ec/buffering-coco.md): 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. (Grower practice) - [EC vs PPM: the 500 and 700 scales, CF, and how to convert](https://genetixbay.com/knowledge/ph-ec/ec-ppm-scales.md): 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%. (Established) - [pH and EC meter calibration: buffers, slope, storage and when to replace a probe](https://genetixbay.com/knowledge/ph-ec/meter-calibration.md): 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. (Established) - [pH and nutrient availability: what pH really controls, by medium](https://genetixbay.com/knowledge/ph-ec/ph-nutrient-availability.md): 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. (Established) - [pH drift in hydro: why reservoir pH rises (and sometimes falls)](https://genetixbay.com/knowledge/ph-ec/ph-drift-hydro.md): 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. (Established) - [Runoff testing: how to measure root-zone pH and EC and what the numbers mean](https://genetixbay.com/knowledge/ph-ec/runoff-testing.md): 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. (Supported) - [Water quality for cannabis: RO vs tap, alkalinity, bicarbonates and chloramine](https://genetixbay.com/knowledge/ph-ec/water-quality.md): 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. (Supported) ## Systems Soil, coco, rockwool, living soil and every hydro system. - [Bottom-watering, soak trays and wick (self-watering) systems](https://genetixbay.com/knowledge/systems/bottom-watering-wick.md): 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. (Supported) - [Choosing your growing system: soil, coco, rockwool or hydro](https://genetixbay.com/knowledge/systems/choosing-a-system.md): 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. (Grower practice) - [Deep water culture (DWC)](https://genetixbay.com/knowledge/systems/dwc.md): 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. (Supported) - [Drain-to-waste drip and crop steering (generative vs vegetative dryback)](https://genetixbay.com/knowledge/systems/drain-to-waste-crop-steering.md): 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. (Grower practice) - [Ebb and flow (flood and drain)](https://genetixbay.com/knowledge/systems/ebb-and-flow.md): 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. (Supported) - [Fogponics: ultrasonic fog for roots (a supplement, not a system)](https://genetixbay.com/knowledge/systems/fogponics.md): 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. (Grower practice) - [Growing in coco coir](https://genetixbay.com/knowledge/systems/coco.md): 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. (Supported) - [Growing in rockwool (stonewool cubes and slabs)](https://genetixbay.com/knowledge/systems/rockwool.md): 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. (Supported) - [Growing in soil (potting mix with bottled feed)](https://genetixbay.com/knowledge/systems/soil.md): 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. (Supported) - [High-pressure aeroponics (HPA)](https://genetixbay.com/knowledge/systems/hpa-aeroponics.md): 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. (Supported) - [Kratky (passive, non-circulating hydroponics)](https://genetixbay.com/knowledge/systems/kratky.md): 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. (Supported) - [Living soil (no-till, water-only organic growing)](https://genetixbay.com/knowledge/systems/living-soil.md): 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. (Grower practice) - [Low-pressure aeroponics (LPA)](https://genetixbay.com/knowledge/systems/lpa-aeroponics.md): 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. (Supported) - [Nutrient film technique (NFT)](https://genetixbay.com/knowledge/systems/nft.md): 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. (Supported) - [Recirculating deep water culture (RDWC)](https://genetixbay.com/knowledge/systems/rdwc.md): 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. (Grower practice) - [Recirculating drip (top-feed, runoff returns)](https://genetixbay.com/knowledge/systems/recirculating-drip.md): 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. (Supported) ## Training Topping, LST, SCROG, SOG, mainlining, defoliation. - [Defoliation and lollipopping: what to remove, when, and the evidence](https://genetixbay.com/knowledge/training/defoliation-lollipopping.md): 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. (Supported) - [FIM: pinching most of the tip for multiple tops](https://genetixbay.com/knowledge/training/fim.md): 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. (Grower practice) - [HST and supercropping: controlled stem crushing](https://genetixbay.com/knowledge/training/hst-supercropping.md): 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. (Grower practice) - [LST: low-stress training](https://genetixbay.com/knowledge/training/lst.md): 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. (Grower practice) - [Mainlining and manifolding: building a symmetrical plant](https://genetixbay.com/knowledge/training/mainlining-manifolding.md): 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. (Grower practice) - [SCROG: screen of green](https://genetixbay.com/knowledge/training/scrog.md): 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. (Grower practice) - [SOG: sea of green](https://genetixbay.com/knowledge/training/sog.md): 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. (Supported) - [Topping: cutting the main tip for more colas](https://genetixbay.com/knowledge/training/topping.md): 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. (Supported) ## Pests Identification, life cycles, thresholds and IPM. - [Aphids on cannabis: cannabis aphid, green peach aphid and friends](https://genetixbay.com/knowledge/pests/aphids.md): 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. (Supported) - [Broad mites and hemp russet mites: the invisible ones](https://genetixbay.com/knowledge/pests/broad-russet-mites.md): 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. (Supported) - [Caterpillars and budworms on cannabis](https://genetixbay.com/knowledge/pests/caterpillars.md): 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. (Supported) - [Fungus gnats: the watering problem with wings](https://genetixbay.com/knowledge/pests/fungus-gnats.md): 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. (Established) - [Root aphids (rice root aphid) on indoor cannabis](https://genetixbay.com/knowledge/pests/root-aphids.md): 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. (Supported) - [Spider mites on cannabis: ID, lifecycle and IPM](https://genetixbay.com/knowledge/pests/spider-mites.md): 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. (Established) - [Thrips on cannabis: silver scars, black specks and how to break the cycle](https://genetixbay.com/knowledge/pests/thrips.md): 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. (Established) - [Whiteflies on cannabis: ID and IPM](https://genetixbay.com/knowledge/pests/whiteflies.md): 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. (Supported) ## Diseases Mildew, botrytis, root rot, viruses and viroids, sanitation. - [Botrytis (bud rot / grey mould) in cannabis](https://genetixbay.com/knowledge/diseases/botrytis-bud-rot.md): 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. (Established) - [Fusarium in cannabis: wilt, crown rot and bud rot](https://genetixbay.com/knowledge/diseases/fusarium.md): 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. (Established) - [Hop latent viroid (HLVd, 'dudding') and other cannabis viruses](https://genetixbay.com/knowledge/diseases/hop-latent-viroid-and-viruses.md): 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. (Supported) - [Powdery mildew in cannabis](https://genetixbay.com/knowledge/diseases/powdery-mildew.md): 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. (Established) - [Root rot and Pythium in cannabis](https://genetixbay.com/knowledge/diseases/root-rot-pythium.md): 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. (Established) - [Sanitation and disease prevention for cannabis grows](https://genetixbay.com/knowledge/diseases/sanitation-and-prevention.md): 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. (Supported) - [Septoria leaf spot (yellow leaf spot) in cannabis](https://genetixbay.com/knowledge/diseases/septoria-leaf-spot.md): 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. (Supported) ## Diagnosis Symptom-led decision trees: start here when something looks wrong. - [Brown or burnt leaf tips on cannabis: a differential](https://genetixbay.com/knowledge/diagnosis/brown-burnt-tips.md): 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. (Supported) - [Brown roots in hydroponics (DWC, RDWC, NFT): a differential](https://genetixbay.com/knowledge/diagnosis/root-browning-hydro.md): 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. (Supported) - [Clawing leaves on cannabis: a differential](https://genetixbay.com/knowledge/diagnosis/clawing-leaves.md): 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. (Grower practice) - [Drooping cannabis: overwatering vs underwatering](https://genetixbay.com/knowledge/diagnosis/drooping-overwatering-vs-underwatering.md): 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. (Supported) - [Foxtailing buds on cannabis: genetics or stress?](https://genetixbay.com/knowledge/diagnosis/foxtails.md): 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. (Grower practice) - [Hermaphrodite cannabis (bananas and nanners): what to do](https://genetixbay.com/knowledge/diagnosis/hermaphrodites.md): 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. (Supported) - [How to diagnose any cannabis plant problem](https://genetixbay.com/knowledge/diagnosis/how-to-diagnose-any-problem.md): 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. (Supported) - [Purple or red stems and leaves on cannabis: a differential](https://genetixbay.com/knowledge/diagnosis/purple-stems-leaves.md): 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. (Supported) - [Rust-coloured spots on cannabis leaves: a differential](https://genetixbay.com/knowledge/diagnosis/rust-spots.md): 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. (Supported) - [Slow or stunted cannabis growth: a differential](https://genetixbay.com/knowledge/diagnosis/slow-growth.md): 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. (Supported) - [Stretchy, leggy cannabis: a differential](https://genetixbay.com/knowledge/diagnosis/stretching.md): 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. (Supported) - [Taco or canoeing leaves on cannabis: a differential](https://genetixbay.com/knowledge/diagnosis/taco-canoeing-leaves.md): 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. (Supported) - [White powder or white spots on cannabis leaves: a differential](https://genetixbay.com/knowledge/diagnosis/white-powder-on-leaves.md): 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. (Supported) - [Yellow new growth on cannabis: a differential](https://genetixbay.com/knowledge/diagnosis/yellow-new-growth.md): 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. (Supported) - [Yellowing lower leaves on cannabis: a differential](https://genetixbay.com/knowledge/diagnosis/yellowing-lower-leaves.md): 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. (Supported) ## Harvest and cure Ripeness, flushing evidence, drying, curing, storage. - [Curing and burping: jars, humidity and how long](https://genetixbay.com/knowledge/harvest-cure/curing-burping.md): 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. (Grower practice) - [Drying cannabis: the 60/60 method and water activity](https://genetixbay.com/knowledge/harvest-cure/drying.md): 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. (Supported) - [Irradiated cannabis: gamma, e-beam, X-ray, ozone, RF and what they do to your weed](https://genetixbay.com/knowledge/harvest-cure/irradiated-cannabis.md): 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. (Supported) - [Long-term storage: keeping cured flower potent and aromatic](https://genetixbay.com/knowledge/harvest-cure/long-term-storage.md): 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. (Supported) - [Pre-harvest flushing: a myth that costs you yield and resin](https://genetixbay.com/knowledge/harvest-cure/flush-debate.md): 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. (Myth) - [Trichome ripeness: clear, cloudy, amber, and what the evidence says](https://genetixbay.com/knowledge/harvest-cure/trichome-ripeness.md): 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. (Grower practice) ## Breeding Genetics, pollination, selection, stabilisation, seed production. - [Backcrossing, IBLs and stabilisation](https://genetixbay.com/knowledge/breeding/backcrossing-ibl-stabilisation.md): 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. (Established) - [Breeder record-keeping and naming ethics](https://genetixbay.com/knowledge/breeding/record-keeping-naming-ethics.md): 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. (Supported) - [Breeders vs pollen chuckers: what real cannabis breeding looks like](https://genetixbay.com/knowledge/breeding/breeders-vs-pollen-chuckers.md): 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. (Supported) - [Breeding autoflowers: getting the trait into a photoperiod line](https://genetixbay.com/knowledge/breeding/breeding-autoflowers.md): 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. (Supported) - [Chemotype inheritance: how THC and CBD synthase alleles pass on](https://genetixbay.com/knowledge/breeding/chemotype-inheritance.md): 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. (Established) - [Clone-only cuts and how to preserve them](https://genetixbay.com/knowledge/breeding/clone-only-preservation.md): 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. (Supported) - [Collecting and storing cannabis pollen](https://genetixbay.com/knowledge/breeding/pollen-collection-storage.md): 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. (Supported) - [Elite clone-only gatekeeping: why the classics live in a few hands](https://genetixbay.com/knowledge/breeding/elite-clone-gatekeeping.md): 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. (Grower practice) - [F1, F2, F3 explained: what filial generations really mean](https://genetixbay.com/knowledge/breeding/f1-f2-f3-explained.md): 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. (Established) - [Feminised seed and sex reversal: methods, with safety notes](https://genetixbay.com/knowledge/breeding/feminised-seed-sex-reversal.md): 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. (Established) - [Genotyping: what a DNA test can and can't prove](https://genetixbay.com/knowledge/breeding/genotyping-what-tests-prove.md): 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. (Supported) - [How to document lineage evidence (GB-ID evidence levels L0-L4)](https://genetixbay.com/knowledge/breeding/documenting-lineage-evidence.md): 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. (Supported) - [Inbreeding depression and hybrid vigour](https://genetixbay.com/knowledge/breeding/inbreeding-depression-hybrid-vigour.md): 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. (Established) - [Mendelian genetics for growers, with Punnett squares](https://genetixbay.com/knowledge/breeding/mendelian-genetics-for-growers.md): 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). (Established) - [Pollination and seed production, step by step](https://genetixbay.com/knowledge/breeding/pollination-seed-production.md): 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. (Supported) - [Polyhybrids vs landraces: what each gives a breeder](https://genetixbay.com/knowledge/breeding/polyhybrids-vs-landraces.md): 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. (Supported) - [Quantitative traits and heritability: why most good traits are hard to fix](https://genetixbay.com/knowledge/breeding/quantitative-traits-heritability.md): 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. (Established) - [S1s and selfing: what happens when a plant pollinates itself](https://genetixbay.com/knowledge/breeding/s1-selfing.md): 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. (Established) - [Seed germination testing and quality control for breeders](https://genetixbay.com/knowledge/breeding/seed-germination-testing-qc.md): 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. (Supported) - [Selection and pheno hunting: sample sizes and scoring rubrics](https://genetixbay.com/knowledge/breeding/selection-pheno-hunting.md): 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. (Supported) - [Tissue culture basics for cannabis growers and breeders](https://genetixbay.com/knowledge/breeding/tissue-culture-basics.md): 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. (Supported) ## Genetics history Landraces, heritage lines and lineages, with evidence labels. - [Craft vs industrial cannabis: did legalisation's commercial model hurt quality?](https://genetixbay.com/knowledge/genetics-history/craft-vs-industrial-cannabis.md): 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. (Contested) - [How hybrid 'strains' emerged](https://genetixbay.com/knowledge/genetics-history/how-hybrid-strains-emerged.md): 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. (Contested) - [Indica, sativa and ruderalis: what the names really mean](https://genetixbay.com/knowledge/genetics-history/indica-sativa-ruderalis.md): 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. (Supported) - [Landrace hunting or biopiracy? Benefit-sharing, consent and cannabis](https://genetixbay.com/knowledge/genetics-history/landrace-hunting-and-biopiracy.md): 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. (Supported) - [Landraces of the world: an overview](https://genetixbay.com/knowledge/genetics-history/landraces-of-the-world.md): 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. (Supported) - [Old cannabis wasn't weak: the "so much stronger than 20 years ago" myth](https://genetixbay.com/knowledge/genetics-history/old-cannabis-was-not-weak.md): "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. (Myth) - [Patents and the gene pool: who can own a cannabis plant?](https://genetixbay.com/knowledge/genetics-history/patents-and-the-gene-pool.md): 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. (Supported) - [Same cut, a thousand names: renaming, relabelling and the shrinking gene pool](https://genetixbay.com/knowledge/genetics-history/same-cut-a-thousand-names.md): 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. (Supported) - [Why everything tastes the same: the evidence that commercial cannabis is converging](https://genetixbay.com/knowledge/genetics-history/why-everything-tastes-the-same.md): 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. (Supported) - [Why strain names are unreliable: what genetic studies show](https://genetixbay.com/knowledge/genetics-history/why-strain-names-are-unreliable.md): 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. (Supported) ## Glossary - [Glossary index](https://genetixbay.com/knowledge/glossary/): 718 terms with synonyms, A–Z and by category - [Compact glossary](https://genetixbay.com/llms-glossary.txt): every term on one line, "Term (aka …): definition. URL" - [Glossary JSON](https://genetixbay.com/knowledge/api/glossary.json): every term, aliases, category, related terms and articles - [Bay Lines](https://genetixbay.com/knowledge/glossary/bay-lines.md): Bay Lines are GenetixBay's community breeding programme: lines bred from member-nominated keepers and documented males, tested and released with full records. - [Bay Trials](https://genetixbay.com/knowledge/glossary/bay-trials.md): Bay Trials are GenetixBay's member-run controlled grow experiments that test growing claims side by side and publish the results openly. - [Cultured Pearls](https://genetixbay.com/knowledge/glossary/cultured-pearls.md): Cultured Pearls are GenetixBay Pearls bought with money, usable only as store credit in the GenetixBay store; they never transfer between members. - [Evidence ladder](https://genetixbay.com/knowledge/glossary/evidence-ladder.md): The GenetixBay evidence ladder labels every growing claim as Established, Supported, Grower practice, Contested or Myth, according to how strong the evidence is. - [Evidence levels L0-L4](https://genetixbay.com/knowledge/glossary/evidence-levels-l0-l4.md): GenetixBay evidence levels rate lineage claims from L0 (unverified) through L1 community reported, L2 breeder reported and L3 documented to L4 lab-confirmed. - [Founding Member](https://genetixbay.com/knowledge/glossary/founding-member.md): A Founding Member is an early backer of GenetixBay who joins before launch, getting first access, a permanent badge and among the lowest numbers in the archive. - [GB-ID](https://genetixbay.com/knowledge/glossary/gb-id.md): A GB-ID is GenetixBay's permanent identifier for a genetic line, seed batch, plant, cut, grow, harvest or document, so records never get lost or renamed. - [Herm threshold](https://genetixbay.com/knowledge/glossary/herm-threshold.md): The herm threshold is GenetixBay's rule that a line whose tester grows show more than 2% intersex plants cannot join Bay Lines, the Seed Club or be featured. - [Jardin](https://genetixbay.com/knowledge/glossary/jardin.md): Jardin is GenetixBay's grow system in development: a controller and sensor kit for logging and climate control, with per-element custom nutrient dosing. - [Mythbusters](https://genetixbay.com/knowledge/glossary/mythbusters.md): Mythbusters is GenetixBay's page of growing myths and their verdicts, with open Bay Trials and finished results marked Busted, Confirmed or Inconclusive. - [Open research](https://genetixbay.com/knowledge/glossary/open-research.md): Open research is GenetixBay's approach of settling growing questions with member-run controlled trials and publishing protocols, data and verdicts for anyone to see. - [Pearls](https://genetixbay.com/knowledge/glossary/pearls.md): Pearls are GenetixBay's community points, in two kinds: Wild Pearls earned by contributing, and Cultured Pearls bought as store credit; neither has cash value. - [Professor Greenleaf](https://genetixbay.com/knowledge/glossary/professor-greenleaf.md): Professor Greenleaf is GenetixBay's character and botanical knowledge assistant, who answers growing and breeding questions from the cited knowledge base and the grower's own records. - [Seed Club](https://genetixbay.com/knowledge/glossary/seed-club.md): The Seed Club is GenetixBay's seed programme run through a licensed partner, offering tested seed lots with published batch records where the law allows. - [Stud Book](https://genetixbay.com/knowledge/glossary/stud-book.md): The Stud Book is GenetixBay's showcase of documented male plants, with selection journals, keeper details and sire credits; males are encouraged and rewarded. - [The Swap](https://genetixbay.com/knowledge/glossary/the-swap.md): The Swap is GenetixBay's pseudonymous, escrowed member-to-member exchange, reviving the Bay's 2009 peer-to-peer roots, running only in the modes local law allows. - [Wild Pearls](https://genetixbay.com/knowledge/glossary/wild-pearls.md): Wild Pearls are GenetixBay points earned by contributing, such as journals, males, preservation and trials; they can move between members but have no cash value. ## Optional - [Lab notes](https://genetixbay.com/blog/): build updates and grow science from the GenetixBay lab - [Fund the Bay](https://genetixbay.com/fund): founding rewards