I have a stick on heating pad on the right side of her tank. During the day I leave for work, so the heater doesn't stay on. Then I turn on her day white light incandescent bulb until I get home. I keep that on the left side of the tank, right above the water to provide more humidity and to give her warmer water. It doesn't evaporate too much to where it's empty. I was debating on which side to keep the light on. The left side sounded better to me also considering she already has her heating pad on the right.