stonecreek wrote:
I am on a well water system with a fairly new expansion tank and all the
water lines are copper, inside the house. Whenever I do anything that
requires turning off the water and partially or fully draining the system,
such as installing a shutoff valve somewhere, when I turn the water back on
it comes out very dark for a few minutes then eventually clears. If I fill
a glass while it's doing this, there's all sorts of black crud floating in
the glass. Wondering if it's crud from the water heater, or from what's
inside the pipes that breaks loose when the pressure is first turned on.
It spits air and water the first few minutes, that's why I am thinking it's
just normal crud build up that breaks loose while it's spitting air. Any
ideas?

thanks

Crud does come up from well and gets in pipes etc. I put in a whole
house filter and it makes a big difference. I recommend an Aquapure
filter. I had a piece of junk I installed myself and bypass always
leaked so I had to turn off water to change filter. Now that arthritis
is bothering me, plumber put in the Aquapure with bypasses and it works
great without shutting off water. You need change cartridge only every
6 months. It is a simple candle filter and removes sediment only.
You'll still see gunk in water for years afterwards when you work on
system until pipes clear.

Frank