We're using 18" Reptisun 10.0 for both of the boys, and they've been getting dark lately, I couldn't think of a reason other than the lighting, and realized it was time to change them. Our local store where we get our feeders doenst carry them, (18" at least) but can special order them.. problem is the price is about$25+. My dad has no problem online ordering though, when repticon doesn't have the size we need (the November show does, the May show doesn't) (they self them at half the In store prices)