He does have two hides, his water dish is in the middle, and I'm not entirely sure where the 28" came from, he's 18-20. The 10 gallon is a temp. thing, he was in a Rubbermaid about a quarter of the size of the 10 gallon, and I had the 10 gallon lying around. I'm using a digital thermometer/hyd. from Flukers. Should I move him back to the Rubbermaid?