Terrarium*** My 50watt red bulb broke so I got my ABF a heating mat(for 10-20gallon tanks) and put it on the side of the tank. He is in a 20 gallon and it is staying at room temperature. I have readings from both the thermometer on the inside and the digital thermometer. After 8 hours or so I checked and the mat was warm, but the enclosure was 70°F. I added another heating mat, older one, same size, and still nothing. What am I doing wrong???