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. 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 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
- Use plain or very weak solution in the fogger; feed roots by another method.
- Float switch interlock on the fogger relay.
- Keep the fogger tank cool; transducer heat warms it.
- 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).
