Advice on Carbon FIlter for Grow room

I am looking for a carbon filter for my grow room, my room is 6.5x6x7 (273 cubic feet) and i have a 6" 400 CFM inline fan which i plan to dial down to fit the 273 cubic ft capacity of the room. Which carbon filter would be best suited for my set up? the flow of my setup would be

CARBON FILTER > DUCT > FAN > DUCT > COOLTUBE > DUCT OUT OF ROOM

right now i am looking at either a can33 or can66 filter, any advice greatly appreciated

From my research it seems to me the Can and Phresh filters are both solid options. Mountain Air filters being a bit better but their cost reflects this.

This is all research no real life testing though.

Personally I like the entire line of Can products.

go with the phresh or can both are good

i'm definitly going with the can filters, the local grow store has a good price on them from what i can tell, but right now I'm unsure of which filter size to choose for my 6.5'x6'x7' foot room, can33 or can66.

go with the can66 for your size of room

mountain air all day long mate there is nothing better. When your running your cooltube inline with your exhaust set up you are adding alot of resistance to the air flow, add to that the resistance of a carbon filter (even an oversized one) and you might find there is no need to adjust the fan speed.

its also worth noting that you should try and get a filter with a 1/3 higher cfm rating, this means there is less resistance from the filter and air passes through your system at closer to the fans origional cfm

Thanks very much for the good advice, im going to go with the can66..

Go oversize and over kill on the filter. You won't regret it.