I use Exo-terra 75watt red bulbs on my 10 and my 20 gallon terrariums. Since they're red I run them 24 hrs. This keeps my my temps right around 90 hot/80 cool. I also have them on adjustable lamp stands so if my temp is a little high or low I just raise or lower the lamp to control the temp. So it acts like a dimmer switch or rheostat. Also I can swing the light away or not have to move it at all move to open my screen tops. It's a convenience that is worth the 15$ for the lamp stand.