# Fogponics: ultrasonic fog for roots (a supplement, not a system)

> 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.

- Canonical: https://genetixbay.com/knowledge/systems/fogponics.html
- Category: Systems · Level: Intermediate
- Evidence: Grower practice · Status: Draft: awaiting expert review (some figures are being checked)
- Stage: Seedling, Veg · Systems: Aeroponics
- Updated: 2026-10-31 · Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay Knowledge Base (genetixbay.com/knowledge)"

## Questions and answers

**Does fogponics work for cannabis?** Fogponics does not work well as a standalone way to grow cannabis to harvest. Fog is mostly water, dissolved salts stay behind in the tank, and roots in pure fog grow fine hair but little mass. There is no published support for fogponics as a complete cannabis system; it works as a humidity supplement in [cloning domes](https://genetixbay.com/knowledge/glossary/cloning-dome.md) or alongside [aeroponics](https://genetixbay.com/knowledge/glossary/aeroponics.md) or [NFT](https://genetixbay.com/knowledge/glossary/nft.md).

**Can [foggers](https://genetixbay.com/knowledge/glossary/humidifier.md) feed plants nutrients?** Ultrasonic foggers deliver very little nutrient to plants. The fog is mostly water, and dissolved salts largely stay behind and concentrate in the fogger tank, crusting the discs and cutting fog output. Use plain or very weak solution in the fogger, dump the tank when its [EC](https://genetixbay.com/knowledge/glossary/ec.md) passes 1.5 times the input EC, and feed the roots by another method.

**How long do ultrasonic foggers last?** Ultrasonic fogger transducers typically last about 1,000–3,000 hours, an engineering estimate worth checking against your transducer's datasheet, and should be replaced on schedule. They run hot, which warms the tank, and running them dry destroys them. Fit a float switch interlock so the fogger cuts out when the tank level falls below minimum.

**Is fogponics good for clones?** Fogponics is good for clones because ultrasonic fog keeps cuttings and new roots at near 100% humidity, with the chamber at 95% [RH](https://genetixbay.com/knowledge/glossary/relative-humidity.md) or higher. Fog into the cloning dome or chamber, but vent daily to prevent soggy stems and mould. Fog carries very little nutrient, so treat it as humidity support rather than a feeding method.

**Short answer.** Ultrasonic discs make a very fine fog (**~5–10 µm**) that a fan pushes into a root chamber [2]. It keeps roots and cuttings at near 100 % RH, which is why it's popular for [cloning](https://genetixbay.com/knowledge/glossary/cloning.md). As a **sole** feeding method it's weak: fog is mostly water; dissolved salts largely stay behind and **concentrate in the fogger tank**; transducers **run hot and die in ~1,000–3,000 h**; and roots in pure fog tend to grow fine hair but little mass [2]. GenetixBay and Jardin treat fog as a **humidity supplement** alongside LPA, [HPA](https://genetixbay.com/knowledge/glossary/hpa.md) or NFT, or in cloning domes [2].

## Numbers that matter

| Parameter | Target | Notes |
|---|---|---|
| Fog droplet size | ~5–10 µm | Ultrasonic; finer than HPA's ~10–100 µm [1] |
| Chamber RH | ≥ 95 % | [2] |
| Fogger tank EC | Dump when > 1.5 × input EC | Salts concentrate as water fogs off [2] |
| Transducer life | ~1,000–3,000 h | Replace on schedule [2] |
| Tank level | Always above minimum | Dry-running destroys transducers [2] |

## How to use it well

1. Use plain or very weak solution in the fogger; feed roots by another method.
2. Float switch interlock on the fogger relay.
3. Keep the fogger tank cool; transducer heat warms it.
4. For clones: fog into the dome or chamber, but vent daily to prevent soggy stems and mould.

## Failure modes

| Problem | Sign | Jardin response [2] |
|---|---|---|
| Transducer dead | RH stops rising with relay on | Alert |
| Tank dry | Float trips | Relay cut |
| Tank EC climbing | Crust on discs, fog output drops | Dump and refill |

## Jardin notes

Jardin method "Fogponics": supplement only. The UI says "supplementary" wherever fog is configured as the only method. Time-to-harm: hours if it is the sole method [2].

## Common mistakes

- Feeding a flowering plant by fog alone.
- Running discs dry.
- Never replacing transducers.

## Evidence

Aeroponics in general is *Established* [1]. Fogponics as a complete cannabis growing system has no published support we can cite; the limitations above are physical and from engineering experience (*Grower practice*).

## Sources

1. Lakhiar IA, Gao J, Syed TN, Chandio FA, Buttar NA, 2018. Modern plant cultivation technologies in agriculture under controlled environment: a review on aeroponics. Journal of Plant Interactions 13(1):338–352. https://doi.org/10.1080/17429145.2018.1472308
2. GenetixBay Jardin engineering notes, 2026 (system profiles and failure margins).