Actually, I'm using 2 UTH's (because we have A/C, and I could not keep cool side warm enough) I have the hot side on a T-stat and cool side hooked to a dimmer. So far, it keeps temps perfect. I had to use two Accurite thermometers so I would know what the temps are in the hides. I didn't feel like playing guessing games. The dimmer needs to be adjusted a few times a day (not by much), due to room temp fluctuations. I only had a problem with humidity being too high, so I changed to a smaller water dish, and will use the larger one at shedding time. I've only had my BP for 6 days so far, but it works for me.