Hmm ... fungus gnats ...
Just guessing, but maybe if you can keep the soil surface drier, and/or run a fan, maybe there would be fewer gnats?
When I want a drier surface, I sprinkle a layer of biggish pine bark chunks onto the surface, like a tiny layer of coarse mulch. At least then the bugs have to burrow through the bark to get to moist soil that have things that can decay or support fungus and feed gnats.
I may be naive to think that would help much.
I like the long strips of flypaper!
