Dry Ice.

I'm pretty sure no. But if someone knows how that would be possible i'd like to know

 

depends on the size of growroom..........you'd need a lot of dry ice just to cover a 3'x3' room.............and if you could have enough of them, you have no indication as to how much is being released.............too much co2 is bad for plants too..............Peace out..........Sid

 

not to mention that too much will freeze your plants to death