Posted: Fri Jul 29, 2005 12:32 am
I moved my turts from a 40 gallon plastic tub to a 120 gallon tank and they've never had problems adjusting. To be honest, I think I kept them in their old tank too long, but they were was no adjustment problems regarding water levels. A 4" RES should be OK in what you described, I would just keep a lookout for areas that he might get stuck in. My turts usually sleep at the bottom of the tank and surface for a breather, or sleep on the area of their basking platform that is completely submerged (but only a couple of inches deep).
A depth of 6-7 inches should not be a problem, however you might want to put some large rocks in there so he can surface abit easier.