As you may know I've made a vivarium out of an old fish tank (24" x 12") I have a 9inch netted section on the front for access and ventilation and the rest is glass.

So far all I've got is a very small heat pad on the back oif the tank (about 4" square) and I 'borrow' an Exo Terra canopy overnight with a 15 watt moonlight bulb in it, from the crested geckos vivarium.

This means the average temperature of the tank is about 18 degrees. Now the weather is getting colder I need to sort out a more permenant way of heating their tank. I'm not really happy using a heat mat as it only really heats the portion of glass it sits on, I was thinking of some kind of light set-up above the tank, but I'm worried about the heat cracking the glass.

Has anyone got any ideas? What kind of bulb? How could I fix it to the top of a glass tank? How would it work out with day/night temperatures?

Thank you, Kerry.