Thanks. That's a great idea. I'm thinking maybe using aluminum foil would work really well to keep heat in. We are in an upper apartment, so our heat fluctuates a lot. We are affected by the downstairs neighbor's heat, and even wind makes a big difference. It hasn't been an issue with the corns, but they have different requirements, and shorter tanks. I'm thinking I may switch them around soon, and move the BP into one of the 10 gallons, and let one of the corns have the 16 gallon tall that the BP is currently in. I'm planning a DIY project for a 55 gallon I have, to make an awesome display tank for one of the corns this summer, but I might switch them around earlier since the BP's needs are more difficult to maintain in the taller enclosure. Maybe I will pick up a heat bulb, too. I do have a fixture for it.