As we scale up indoor propagation, we've run into a fungus gnat outbreak. It's mainly around some plant propagation shelves we setup, but they are also in the bathroom and tons in the kitchen near the window and sink especially. We've tried covering the soil with sand, added tons of big non-toxic yellow sticky traps, and are trying to keep things on the drier side without killing cuttings as they root. None of this seems to be enough! We learned predatory nematodes might be the solution, tipped off by the internet and a local farmer. I wanted to pick Permies' brains before giving that a try though.
Does anyone have experience with IPM for fungus gnat control, using nematodes or something else?
Is there a risk that the nematodes themselves will become a problem? Does their population decrease and stabilize or go extinct as the gnat population decreases?
Given nematodes are the most abundant multicellular creature on Earth and my soil is most likely teaming with varieties of them already, this is probably not really an issue.
Are they safe for indoor use?
The internet says yes and harmless to pets (we have pets).
The thing I'm most concerned about is the unknown unknowns, which seems to bite humans in the ass with biological controls on larger scales. Thus, I ask you my fellow Permies: are Steinernema feltiae
a good response to fungus gnat infestation?