I have searched this and other forums and cannot find an answer. I just got HTG's 4" fan and filter combo. I have two ak47 bag seeds going in the third, almost fourth week of veg(they started stinking this week at the new node site) My closet is 16 cubic feet and my cfm rating is 170 where I only need like 3.375! Anyway, there is negative pressure, no skunk smell unless I open the door. Here's my issue. To me, the exhaust sorta smells like a stale, hangover fart. Is that normal? The carbon itself has the odor too. It only smells like this in my "man cave" where the closet is. I don't think it's a problem, but anyone else experience this?