I'm using a Flukers digital Thermo-Hygrometer that sticks onto the side of the tank. I love it. But for checking hot spot temp where the UTH is located I have a ZooMed Thermostat. I can't afford the ridiculous $300+ ones right now, so it works pretty well. No temperature read out, but not too hard to figure out at any rate. Plus, it was not that expensive if budget is an issue like it was for me. The digital T-H is $25 at Petsmart and the Thermostat was $30. Not too bad overall.