What watt should I use? See.. I went to petsmart to get a light bulb and the dude recomended a 50 watt... I came home yesterday and found that my poor baby Kyna's terrarium was 72degrees!!!!( MY POOR SWEET BABY!!!!!*cry*) So I have a 150 watt now but its way wayyyyy to hot to put directly over the terrarium. I dont have anything in which to mount it on so ...it has to be on top of the lid... would a 75 watt or a 100 watt work better? ( my house is rather cold...)