It's big, but it would do shit. Too much room for air... you'd be breathing too much oxygen, you'd have to smoke for an hour to have anything happen. The smaller the better is actually the fact.
Smaller is not nessecarily true....trust me......id know.......
My friend and me constructed a little sometinh we like to call the five sixer. Cut off the bottom of one of those deer park huge water tank things ( like 15 gallons) and we put a fan on the bottom of the lide, then duct taped it shut.s Then we proceded to put in a shotgun, and the rigid plastic pipe that 5' 6" tall to hit off of. 3 hits off of that thing and you were gone for the night.