Dude i saw a message you posted about a few months ago... figured i would give you my advice since noone gave you a better answer. You should vent your area and your light seperatly... Send an inline fan past your cooltube and out the other side of the tent box or whatever the hell you use and there is no need to use a carbon filter. Attach your carbon filter to the other fan that you have venting the entire area. And bam.. you have two seperate ventilation setups which run much more efficiently because they have less of a puzzle to travel through (eg) Ducting = Fan = Cooltube = Ducting= carbon filter.