A lot of people don't agree with this, but I've been doing it for years with inside turtles. I use a screen top. In the middle or off to one side I put the heat emitter and along the center toward the back I put the long tube 5.0 UVB. If you walk in the woods and if you are lucky to see any box turtles on the forest floor, you will see that the only sun they get is filtered through the trees. So the screen top is not harmful. Also mine are out in the garden all Summer, and then only the babies or anyone sick comes in for the Winter. Just what I do.