I grow in all mixed org soil, and always just throw my yellow fans and shit I pull in the top of the buckets, and never have a problem with white flies or anything indoors... I do also let lady bugs live in my grow as well, which I think may be the reason I don't see any other living things in there, like I have before, many moons ago.... I did have a small whitefly outbreak during my last veg, after I had mixed new soil, but I'm sure I had brought the flies in with the soil then, but the lady bugs sure have earned their rent... I dont have fly one, and don't haveta use neem oil/water foliar sprays anymore during veg time either... Id imagine theres a shit ton of different environs on here though, so itz probly different for everyone... I can't speak enough on how awesome a nice healthy, living soil is to grow with, though...