[GarterGuy]

Temperature gradiant is really the way to go. Raven should be able to decide exactly how warm or cool she wants to be at any time. Just keeping her at one temp. doesn't allow for this and the fact that the radiator isn't hooked up to a thermostat, that measures the tank temp., there's always the possibility of it over or under heating the tank. The temp. range you gave is a good range, but not all at once. Raven should have a choice of the cool end or the warm end.