I have an ionizer (bout 2 and 1/2 feet tall) made by Sharper Image, I don't know if it does anything, good ventilation seems more important to me. Or a carbon filter. Those little ones are a joke, in my opinion, I wouldnt bother. I have decent exhaust, the ionizer, and the smell is ok so far, but I'm only in week 2 of flowering, so it could get worse. I've been told you need an exhuast fan going out that pumps out the entire room (closet, box whatever) in 1-3 minutes.