Alright, so I bought a UTH for a 10-20 gallon tank.

My next question is if anyone here has used these on the side of the tank. My original purpose for buying it was to generate some heat from the bottom up, but I have nothing to put my tank on except my wooden dresser next to my bed. The instructions say that you can place it on the side, but I want your opinions. I'd really prefer to put it underneath, I just can't find anything to put between the tank and my wooden dresser to prop it up.