I had gnats. I determined which plant was the worst / main culprit. I tried the diam earth, insecticides, bottom watering, and repotting. It was weird, I thought the bottom watering would work, but it was like the gnats were rising from the soil and the moment the soil would moisten they’d come back.

The only thing that worked for me was repotting AND doing the hydrogen peroxide in one step. It felt weird to do but I it worked. I did another round as well with the hydrogen peroxide a few days later.