Are you saying Roots Foods..? The best thing you can do is get yourself some "Gnatrol" , a small pkg from Amazon is only $2.85 and I cannot say enough about how well this stuff works. I just ran out and need more.. mix in a tsp with a gal water and walla... kills em all, after a week hit them again and they should be gone.. stuff is like magic killing them gnats..
Organic foods can have stronger smells to them and thus attracting the bugs to it.. seal up that room and caulk them cracks up man.. lol. but really, most of us deal with them at one point in our grows, some worse then others like me who lives in a swamp.. plus I recycle soil 3-4x's.. eggs get passed along.. but the Roots Organic Food and Soil to me is the best stuff on the market especially for Auto Flowering... I did an entire grow without adding any nutrients and they grew fine, just fine..
good luck man