I have a 20 gallon long glass terrarium with a screen top set up for my ball python. He is going into his first shed and I am trying to keep the humidity up by misting the enclosure and covering half of the screen top. The problem is that I have the CHE (ceramic heating element) on the other half of the screen which doesn't leave much space for ventilation (about 4"x12" open screen) I was wondering if there are any tricks to preventing stagnant air in a glass terrarium while maintaining proper humidity levels. Thanks!