I am a first time grower, with three plants in a closet lined with aluminum foil, and a layer of garbage bag on the floor, a fan and an ionizer. I had a bad case of fungus gnats, and I think I might have brought them in with the store bought soil I used first. I tried hydrogen peroxide, and that didn’t work, and I also let my plants dry out, and that didn’t get rid of them completely either. I heard about mosquito dunks, you crush them up and sprinkle them on the soil, and I also bought two fly paper strips and hung them up, too. After one day the fly paper strips were completely filled and I was shocked. You can’t always see those little suckers, but I evidently I had a worse infestation than I had thought. I looked closer down at the floor and I saw one crawling on the black garbage bag. I pulled the plants out of the closet and ripped out the garbage bag and ah hah! There were hundreds of them down there. So they don’t always need soil to attract them. They are attracted to moisture and dark places where fungus can grow. So I learned something. No more dark garbage bag plastic anywhere around my grow. Thought you all might like to know. Cheers!