md, from what i have read for co2 to matter you want to run a sealed room and have between 1500-1800ppm.

if you want to use it to any kind of fruition, you would probably want to run a system that monitors and releases the gas as needed (don't know all the technical jargon as i do not have enough experience or the other proper equipment to take advantage of co2). furthermore, you want to have all the other aspects of your grow dialed in before journeying down this path or it's just gonna be a waste.

also keep in mind that co2 can kill you and your animals.

just my $.02.


-shake