O.K. Temperature fluctuates a lot. So I got this thermostat with heater. It will automatically turn on or off, depending on the temp. of the water. (regulates it) So, it looks alright but I wasn't sure if the metal is OK. All my heaters are glass.
Yeah, I keep 2 in the sump as well. Never had an issue till this summer, I came home to tank at 81, where before it held between 76-78. But it still does fluctuate a couple degrees a day which I understand isn't good.