Quote Originally Posted by river-wear View Post
OOPS!

Waterbear: dumb question for you - does the water always circulate through the heater even when not in use? At least in a standard setup? I imagine different pools could be plumbed differently. I'm not sure so I'll have to look at mine, but I had assumed (yikes) that it was bypassed when not used.
Yes, normally, unless you have a bypass plumbed in and you turn the valves to bypass the heater. This is the exception rather than the rule since heater damage can occur if fired up with no water flowing through it.

In answer to your question - the spots were orange.
That would be iron
I'll look into the CH (Calcium hardness, right?) to prevent new problems from cropping up though. I know the city water here doesn't typically have a lot of mineral content. If I need to increase it, how is that done?
Hope this helps