The wall between the flower/grow compartment is sealed with velcro, there was some light leak I sealed with duct tape because of the different light cycles. The grow/clone side should have some air movement because it does get a little warmer and the carbon filter isn't drawing enough threw. I may have to add another fan to such out the warmer temp and get the air moving.Those florescent lights were on sale at local Canadian Tire for $10 each. I bought three and mounted them together and they been working awesome