S
Speedcat
This will nto get every one but will slow down your population for cheap. Get double sided tape and run some around the rim of your pots, replace whenever they become non sticky or full of dust ect. I tried this with duct tape before I used double sided sticky tape and i noticed they like to crawl the rim of pots usually and then down teh side of the pot so this helped with whenever teh fuckers wanted to touch the rim of the pot theyed die a sticky death. Now if you have a large grow this can be time consuming but Its more effective then hanging sticky tape everywhere since fungus gnat adults seem to crawl more on the surface then fly. use this in conjunction with Gnatrol WDG off of ebay for cheap and you ahve a solid setup.