The UTH that I purchased came with little plastic footies that I could place at the bottom of the tank to allow airflow. It was a reptitherm UTH.

I use both lamps and UTH with dimmer switch to make sure that the floor isn't getting too hot. The only problem I am having now is that my ambient air is getting a little too warm during the day and warming up the cool side. I switch to the red bulb at night so I can still offer some ambient warmth but keep the harsh light away.

Hopefully I could help some...I am a newbie and still feel a little funny offering advice lol