Actually i think it will be smart to buy one.

I am going to be making a grow room using a bookshelf (2.5'L, 1.5'W, 5.5'H) wrapped in panda film. Would this carbon filter with a 240CFM fan be adequet for an exhaust system?

8 X 14 ACTIVATED CARBON ODOR SCRUBBER WITH 240 CFM

Is that a reliable one to buy, because it is way cheaper than most places at $150

or can i go smaller with this filter using a 130 cfm fan?

6 X 14 ACTIVATED CARBON ODOR SCRUBBER WITH 130 CFM FAN