Right now at this moment im using a 39 gal tall tank for my ball and i live in Canada so in the winter months i had to develop a sure way to keep my temps and humidity up. Heres what i did, the tank is much taller than what i need at 18" but my other tanks are to big for him just yet so i used a UTH that covers just under half the bottom. I also covered the top with tin foil and duck tape just as in the sticky for glass tank setups
http://www.ball-pythons.net/forums/s...0&page=2&pp=10

I put a heat lamp on the cool side and used a purple 50 watt bulb at first and found that it wasnt getting the ambient temps warm enough so i switched to a 75w infared and up they went but a little to high. Up to this point i've been using a crappy zoomed 500r thermostat for my UTH (which im changing to a ranco as soon as it arrives) and not wanting the light going on and off all day and night in my room i decided i would put a good lamp dimmer from homedepot on it and works well. Every morning when i get up to check for waste and change water i adjust the dimmer for my ambient temps if needed ( i usually dont have to touch it unless theirs a big swing in room temps).

So know that my temps were sorted out with a UTH on a thermostat and heat lamp with an infared bulb on a dimmer, my top foiled and taped up i was good for temps and could keep them stable by just checking daily, no problem. But now because of the heat lamp my humidity was suffering large dropping down to 20% on a daily bases, no good. I then went out and bought a replacement element and adapter for an ultra-sonic fogger. The kind that you see at Wal-mart for decorations the make the cool mist in the glass bowls. I put it in side a large peanut butter jar and cut a slit a little more than half way up across the middle around 4 inches long. Placed it ontop of the tank with the slit just over top of the vent opening and plugged it into the thermostat. Now every time my UTH clicks on so does the fogger and it rains down a mist into the tank keeping my humidity up around 55%. Before this i was misting 3 times a day and now i dont half to touch anything.