building a sealed room

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!

led with sealed room no co2 yet, you wont be getting much. really for good flowering consider hps with venting or co2. actually, skip sealed room for now,grow with venting get it dialed first

I actually just purchased the magnum led grow light. Gonna see how it goes in flowering. I also have an led illuminator pro which gave me a fairly decent yield for my past few grows. Thanks for the advice.