Found this one on Ebay (even though bidding has ended). I'm thinking I could just put this in the grow closet with my plants. I think I'm going the best route as opposed to a carbon filter.
eBay: FRESH AIR 300-1300 mghr PURIFIER OZONE GENERATOR ALPINE (item 120114118738 end time May-04-07 16:45:10 PDT)