No problem, as long as scrubbed air is re-circed w/ in the hut, and not exhausted.

If you can smell from outside the room, suggests air exchange even when vent sys off- you're losing CO2. You might want to think about a back-draft damper on the exhaust, if yer fan will handle it.
Also make sure little flap-covers on the intakes to the hut are closing all the way.

Often a good idea to run duct from internal scrubber to top of space if filter low, bottom if filter high- you can use it as a de-strat as well.
rhizome Reviewed by rhizome on . Can you run a carbon scrubber while running co2...?? Can some one please tell me if running a carbon scrubber while running a co2 tank will deplete the co2...i hate the smell my grow room gives off when i have the exhaust fans turned off and the co2 on ...I:D have another exhaust mounted carbon scrubber that clears the hydrohut after the co2 cycle but i smell the odor while the exhaust is off and co2 is on.. I plan on adding a non vented carbon scrubber for just this purpose .. to scrub the air within my hydro hut but not vent the clean Rating: 5