Oh that's a good idea with the water! I am really worried to leave anything on at night or if I am not home. I might get a heat pad for the side of the tank but since they're not really re stickable I'll probably wait until she gets her new tank. I noticed my night time little 25 watt bulb is doing a good job. I put my hand in and I can tell it is a few degreese warmer in the tank than outside of it.