That is a wonderful idea Alot of people do cover their screen tops with plexiglass (including myself, its complicated because I use damp towels too, but that is because I have a tall tank) Set up one is best because it helps the cool side stay, well, a little less cool. The UTH on the warm side is enough to keep temps of about 90 degrees while the overhead lamp on the cooler side helps raise it above room temp.

I had my tank set up like number 1 for a while, then I purchased a second UTH to provide constant 84 degrees on the cooler side, because the heat lamp only warmed the air, not the area under the hide on the warm side. My house is also very cold so a second UTH was the way I needed to go. Great thread!!

And don't forget to use a control device with your UTH! Uncontrolled they reach above 110 dgrees which is way too high. Another reason you need a digital probe