I went through quite a few heaters when I started...seemed like everytime I turned around one was failing and would only be a month or two old. I did some research and tried a Jager Thermostat Heater by Eheim. Best thing I ever did. This heater works like a champ. You can calibrate it, and it is fully submersible. Dr fosters has them on sale right now. I do not think I will ever use a different heater again.