I am in the process of building a sealed flowering room in which I plan on eventually using c02. I will be using LED's as a light source so I'm not really concerned about temperatures. My question is, should I vent the air out of the room through a carbon filter using vents? Or should I just hang it above the plants? My plan was to just hang it above the plants, and use a separate fan on a timer (possibly with a second filter?)to refresh the air once in a while. Thanks!