[rohrmann]

The white stuff in the water heater is normal, and a good reason to annually drain the tank and flush it out, checking/replacing the anode at the same time. The water heater water does not go to the the toilet, so what you saw was just mineral deposits from hard water. I purchased a Watts water softener several years ago, and it made a huge difference in hard water deposits on fixtures and in the screens of the plumbing system.