hey someone linked to my advice... sweeet

lol

the home made carbon filter is very effective, and very cheap. keep in mind that there are many other ways to build the same thing.

more importantly, consider what type of ventilation you have. adding a carbon filter will add a lot of drag to your ventilation, requiring a much stronger fan to push air thru the filter at a rate that would continue to maintain your temperature in a good range... my stanley blower was too noisy for me, so i switched to an ozone generator that i found online for $45

ozone is also very effective, but you have to be very careful, it can be hazardous to you and your plants if used improperly. i have o3 damage on my current plant because i was careless with it when i hooked it up for the first time