humm....i was thinking it seemed fast too. i'm going to wait it out a few days and see if it slows down. i have one hermit right now, but i just got him to have something to watch in the tank.
Why do you want to cool the water down? Not sure on this, but I think that although 78 is ideal, 80 degrees will probably be ok. Somebody please correct me if I'm wrong though...my new future reef tank is stuck at a steady 81 degrees right now.