probably dont, here in bc i can get a tank, regulator and gas but my grow isnt big enough to warrent 1, i figure. also this is true of gases, my story; i was using ozone to kill black mold. as i have a bad back i decided to sleep on the floor on a mattress about 1/2 height of my couch. in the middle of the night i awoke with a pounding headache so i got up and took a couple of tylenol 3's and laid back down on the couch. headache was gone and asleep i went to awaken 3 hours later with a headache again so i got up. opened the door and got some fresh air; then i realized it was the ozone gas. if this was CO2 gas i would not have woken up at all. it is dangerous fer people and for pets that sleep on the floor. i have a buddy that killed his best friend; a border collie this way. maybe in an outside building or greenhouse BUT NOT IN YOUR HOME. CO2 needs constant monitering and equipment checks, not worth it IMHO. but its yer life.