sweet stuff. my buddies just built an inline carbon filter for their setup. Its 4" ducting and an inline 180cfm fan pulling air out of a 3x4 room that has a 1000watt. It is essentially just some 4" duct adaptors slid together and taped, filled with activated carbon from an aquarium shop, and capped on both ends by some duct filters. They are only 2 weeks into budding so the smell isnt very strong yet, but already it makes a considerable difference. It can be easily refilled as well.