Carefully aerate the soils, starting at the edges of the pots, taking care not to disturb the roots. Put on a dust mask, preferably paper N95, cover your arms, wear rubber gloves and close fitting glasses...then scoop about 4 Tablespoons of diatomaceous earth on top of soil, and work into the top 3 inches, being careful with roots. The little creatures bleed to death as they hatch. If adult flies persist, and your grow is not flowering, spray neem oil mix just before lights out all over soil and tops and bottoms of leaves. The flies will disappear , but you may have to repeat once weekly to break their life cycle. Again, protect your lungs, eyes and skin. Do not breathe diatomaceous earth dust or neem oil spray.