Fungus gnats can be a deplorable situation to deal with. Most internet research points towards sticky pads and waiting their life cycles out, or placing sand on top of your dirt. After fighting these insistent little buggers, for weeks on end i can tell you that no the sand did not stop them. The sticky pads were unmistakably catching a lot of them, but they were still a nuisance. So we waited the cycles out, but it seemed like there was more of them everyday. They feed off of root rot due to overwatering and fungus in the top layer of the soil. Eventually we came across diatomaceous earth! everything got a healthy coating! The fungus gnats seemed to die down a little and suspicions started to increase that they may be breeding and living in the drainage holes. So to be sure, all plants got a dose of powdered pesticide in their trays. This new combination allowed us to remove the sticky pads and feel a close victory. The fungus gnats lay their eggs in soil, and at a point after being sick of fighting the good fight against them, we just removed the dirt and put them in water. Fungus gnat problem? no problem with no soil 🙃