I've found no matter what with glass tanks that have mesh lids, you're going to have a tough time with humidity. It stinks because I love the way they look! It's just such a pill to keep the humidity right. I switched to large tupperware containers with drilled holes (sanded/smoothed down). The WeatherSeal and locking sides keep the snakes from escaping, and I NEVER have problems with humidity--on the contrary, I actually had too-high levels of humidity with a few holes drilled, and needed to make a lot more. But now it works great, and temps and humidity are ideal. It's just not as pretty as glass.