I was thinking about using mr bubbles carbon filter post to build one...I just need to know the size I should use to make mine for my setup... What length / depth should I make mine for a 4'x4'x6' grow tent with hps 400 and vortex 6" exhaust fan?? http://forum.grasscity.com/general-indoor-growing/330714-mr-bubb-es-carbon-filter.html I think the one in his tutorial here is like 22" long and 8" deep. I'm not sure if I should make mine like his or smaller or what?
I'd say copy the one in his post and see how you like it. From there if you want it smaller, build a smaller one. If you want a larger, build a larger one. Trial and error is fun.