Allright I was thinking about buying a carbon filter agaisnt the smell, but I HAVE NO IDEA how to set one up or even what to do with it? From what I've understand there is a fan on top of these carbon filter cans right? And then you can choose to have an airline conduct it? please tell me, because I want to control smell (closet grow, 250 MH/Hps, 3 feet by 3.5, hight ceiling) But I don't want any airlines, because I don't want to put a hole in the wall. I need some really good info's on them and how to set them up, I've been googling all morning and all I get is shit being sold online. Otherwise I was thinking about buying a Uvonair (what size would you recomend, but these are a lot of cash). PLEASE HELP ME!!!!!!!!!!!!!!