FWIW, I've got two adult BPs in a single T8 with a divider. Right now, I'm using a single piece of 11" heat tape (regulated by a Herpstat) down the center of the T8 to heat the T8, along with two fluorescent lights (one one each side), and temps in the T8 are great. I made the switch about a month ago and am so glad I did. If I could figure out somewhere in my house to fit a second T8, I would pick up a second one for the current sales price.