For once I don't agree with llovelace. That 1/4" gap up top lets the heat take the humidity right out of the tub. That's why no gap and holes on the side works better. The heat can rise but the humidity will stay inside. I still think your problem is too low humidity. I'm more north than you but the same temperate climate and my room humidity is mid 30's. I would guess you are lower due to the area you are in being warmer than up here. I have far less holes than a 1/4" gap around the top of the tub and my tubs stay 50-60%. Unless you are measuring it or using a humidifier in your room I bet it is 30% or lower. This CAN and WILL cause RI in snakes. Which ones get it and how soon depends on their overall health. Obviously your temps are good so that leads me to believe that your tubs are waaaaaaaay too dry. Best of luck Sean! I hope you get it figured out.
Regards,
B
Thanks man, I think im gonna go get a gauge and see what the humidity is. If its too bad Ill have to modify the rack to raise the tubs and ill drill holes.