I Think this Odor filter design Borders on Genius! For my 2X4X5 Ft grow tent I use a expensive 4" 200CFM inline Duct Fan. My DIY Carbon filter is from another post on The ultimate odor control thread https://www.rollitup.org/t/2-minute-cheap-easy-carbon-filter-
no-duct-tape.58871/
I will definitely be making some carbon filters from this thread ASAP. [For a smaller DIY Grow Box for AutoFlowers] I just wanted to mention I bought 4lbs Bulk Air Filter Refill Coconut Shell Granular Activated Carbon Charcoal from Ebay for $24. That would fill about 25 of these filters. http://www.ebay.com/itm/201002362510?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
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