To both of you, THANK YOU very much for your input. I greatly appreciate it both. As for the UTH, thank you I had not thought about the heat! fortunately that isn't where I keep the tank! I just had to down there to make cleaning it easier. Also, no I had not thought about the cardboard collecting bacteria and mold, but fortunately I am trying my make some more hides out of clay and by milling out some other large rocks. So, again to both of you, THANKS for the input. Both of you had great ideas.