charcoal

If I'm getting a vortex s line 6" fan (374cfm), would it be best to run a 6"x16" carbon filter(400cfm), or a 8"x20" carbon filter (730cfm)? Its for a 4x2" flower tent. I think the 6" is the best value, but I have seen some people use bigger filters than fans. I'm planning to use a variac 3 amp...

Alright, newb question here. I'm having a terrible time figuring out where the charcoal filter/odor scrubber should go. Is this order correct? Duct --> Intake Fan --> AC Reflector --> Duct --> Charcoal Filter (air expelled outside) Would I need another fan (lower CFM than the intake fan) to...