Welcome
http://www.amazon.com/Chaney-Instrum...6186577&sr=8-3
Unless you are using a light (hopefully you use a UTH regulated by a thermostat/rheostat), you shouldn't have too bad of issues with humidity if the top is halfway covered. I've had nothing but successful sheds with my ball in the tank (the rest are in a rack). Sometimes I mist a couple times a day if needed, and I use aspen. I guess it depends on where you live but I'm in MA and haven't had issues. With that themostat/hygrometer, I believe it had two probes, you place it in the center and put one probe on the cool side and one probe on the hot side. Do not use tape, if it doesn't come with suction cups you can use hot gluegood luck and welcome to the site.