You should use neem once then switch it up with another spray with essential oils. I found this stuff that is the only organic spray approved by the usda called green clean little bit pricey but they also make one for the soil kills all larva and helps with root rot. Spend 6 bucks buy a hot shots no pest strip. I hang one in my room for a day once week for prevention till flowering starts.Also spray real well with ortho home defence around the out side to prevent any from getting in. Amazon has lots of products with ppls reviews check it out. I also heard putting sand on top of soil helps prevent knats.