Quote Originally Posted by cbianco
I know that lime is different than calcium but the build up is the same idea in my eyes.
Lime is calcium carbonate. Chemically its the same thing as aragonite, live rock, limestone rock or hard coral backbone. Lime has a tendency to precipitate whgen there is a change in temperature (as in a water heater) or when there is a pressure change (like when water goes from a pressurized pipe to 0 psi as it goes through a faucet.) Doesn't that make sense?