I just wanted to let you know: The bad humidity in the tanks was CAUSED by the towel. Towels soak up moisture, and harbor bacteria. When the towel dried it sucked up the moisture from the tank. The best way to retain stable humidity levels in a tank is with the foil treatment or solid plastic.

Tubs look good, tho. Good luck with them...I've found that tubs are MORE trouble for me than tanks.