Tested the products for this filter, works like a champ! Grow system is in a closet, so I used a collapsible ventilation duct with an 8-inch industrial fan as the exhaust. With 12 pre-mature plants, I expect full odor and dust control of up to four superior flowering females. Kinda have to go heavy on the activated carbon and filter fiber, but with the ventilation duct it all only cost me $20. On the subject, though, what's the difference between activated carbon and zeolite crystal?