Use Neem Oil. Mix 1/2 tsp. neem oil and 1/4 tsp. mild dish soap into 1 liter/quart water (I prefer distilled), shake it up reakl good. Now spray the WHOLE PLANT, underside of the leaves and all, and spray the hell out of the soil. Repeat this every other day for a week, you will still see the gnats, but they will not be able to reproduce, kinda like bug-genocide. The adult gnats are harmless to your plants, it's the larvae that hurt the plants by eating the roots. You can also mix a slightly stronger solution and spray the rest of the grow room to be sure that they don't come back.

Also this is a safe solution that can be used except in the final week of flowering.

Hope this helps.


L0rdsOth