Air scrubbing?

Hey guys!

Almost done with my design for my grow box! Woohoo!


All I need is some ventilation help. I have a mini fridge, about 6 cubic feet, and I'm trying to make sure there is enough CO2 in the air. The guy at the grow store said to "scrub", or recycle, the air, but I'm not too sure what that meant... Can anyone explain exactly what that is, and how to do it?


Also, will this make my box smell proof or will I need to do something else?


Thanks in advance

He might of meant to keep fresh air flowing in. Basically make sure you're ventilation actually moves the air out of the box, and the intake brings in nice fresh air. Also, if you are concerned with the CO2 levels you can always put a CO2 generator in there. A good jerry rigged method is to put some yeast in a water and sugar mixture. The yeast eats the sugar and produces CO2.