I cant get these things out of my rez, Ive cleaned the tank and bleached it, they come back, I put a shit ton of 33% H202, they swim in it and laugh, I dumped enough pyrithium in the rez to kill a cow. kills a few maybe but not enough to notice. I bought mosquito dunks and used 300x the recommmend does, they loved it. Then I bought some real expensive liquid drops for mosquitos,flies and gnats, One drop is supposed to treat 50+gal, I put 6 drops in my 30 gal. It did nothing. I have a few of those gnats that fly around and get stuck on the yellow stickys, I think this is there larva. They jump like little fleas and slowy seem to grow to almost a tiny thin worm. I cant seem to get any focus on this point and shoot to get closer. The plants are losing yeild from it for sure so i am pretty sure they are root eaters. From my research I assume thrips or fungas gnat, but I have tried all their known chemicals with no results