you said they will be in cooltubes...If your going to put in Co2, just vent the cooltubes thru a scrubber...w/ the Co2 you can seal the room....like in the 3 lbs. a light thread by Tranoble...Are you trying for trees in those 5 gal.

__________________
With a little imagination, courage, and ambition, anything you desire is within your reach...
It's always 4 TWAMP in the dirty five thirty!!!
People seldom recognize opportunity, because it comes disguised as hard work