ill tell you what I did , you can go from there if you like the idea... I took a 5 gallon bucket cut a hole in bottum to fit air duct tight, cut a piece of screen a little bigger than hole in bucket and put it over hole in bucket. Get some sorta thing you can use as a filter medium.. I use furnes filters cut to fit then I buy carbon that goes in a fishtank filter , small pellets , or crushed small..and sprinkle a lose layer on filter medium I do this 3 more times filter, layer of carbon, filter, layer of carbon....and so on I have the bucket mounted 6 in from celeing siting up right in the corner..air gets pulled through the bucket through the duct through the light hood through more duct then a inline fan then down through my closet floor .....no smell ,,, change carbon every flower cycle...keep filter medium spray with fabreez...good as new