I have a friend who said that her water tank is turning to serious slush--can't pump any more water out. It's not the pump, it's not the plumbing, it's the tank, and it is crystallizing in there big time. If they can't reverse this, they end up w/an 800 ice cube. And yes, the tank is buried. That's a little spooky--never heard of a buried tank freezing! Ideas welcome . . .