I found it critical to ensure that you have a proper filter/blower combo. Make sure that the filter is of adequate thickness to accommodate the desired CFM blast. It is said that the air particle must take minimum .1 seconds to travel through the charcoal bed to be effective. So, if you are pushing 200cfm through the filter you will need at minimum an 1.5 inch thick filter (this is the actual carbon bed thickness) For 200 cfm, at least 14 lbs of carbon will do . I found most of the generic filters sold in hydro stores inferior. Get a can-filter series. They work !! Now ozone also works but you have to be careful not to breath too much of the o3. Direct O3 may also cause plant damage. The filter though is IMO the best way to go and should give you 100% protection........BUT... are condoms 100%? There's always that chance of a little escapement. Best bet is to go ahead and supplement with a low level ozone unit like CAP's Junior. It's timed so you won't OD on it.