i have had these buggers, been using roots organic (green bag)
i have been using DE, sand, sticky traps, bti, and gognats. they have eaten my roots, lowered my yield by 50-80%
i also switched to coco mixed with perlite, wormcastings, bat guano. i have noticed a decrease in the last few weeks. but i just bought a new bag of roots organic and it was stored outside. thinking of not using it now that i hear about others having problems. i dont want these fkers back they destroyed my harvest for 4-5 months. its also very difficult to clone when you have fungus gnats, as they attack the roots are they are trying to grow.
i am going to be pissed at my local grow shop if they knew they were selling bug infested soil. and its a Aqua serene store (Roots organic sibling company)