Thank you for the response, my heat mat is plugged into the temp controlled thermostat and the ambient is measured with one of those digital thermometers although I don’t know how good it actually is the hygrometer is out of sight in the back. I don’t know how much humidity I might lose with the CHE but it might be a good thing I spray that dang tank twice and it jumps to high lol. How important is the substrate temperature? and Is substrate temperature referred to as surface temperature?