[GoatRider]

I have noticed some kind of contaminate in my (bathroom shower) tap water a few random times now, I wonder if anyone has any ideas?

Symptom:
On 3 or 4 occasions, always while waiting for the hot water to reach my master bath shower in the morning (hot water on full, cold shut off) I have noticed a dark "blotch" of contaminated water come out (and shoot down the drain.) Unfortunately I have never had a good look at it, because at that time I am usually naked getting ready for a shower and have my eyeglasses off. From my rather blurry observation, it looks like a few ounces of "rusty" water comes thru the hot pipe. (Also hard to tell because the shower tiles are not white, but appears to have a red or brown tint.)

Other possible factors:
I have an electric hot water heater that is 5 yrs old. I checked the bottom electrode (after replacing these before in prior house) and it shows only minimal signs of corrosion, which is actually white, not brown or rusty looking.
I have a "whole house" water softener, that was there when I bought the house, so unknown age, could be anywhere from 5 to 30yrs old. It still works, as I can tell the difference in water quality when it is allowed to run out of salt. (I do have a bad habbit of letting the salt reservoir run out often.)
Copper piping throughout the house.
On a more regular occasion; like every couple weeks for half a day at a time, the water from all taps has a TON of small air bubbles. It appears cloudy actually but if a glass is allowed to sit, in 5 minutes it clears up. (I think this is caused by the water softener doing some sort of regen cycle?) Not sure if this is a symptom or unrelated.

Let me tell you the first time the dark crud thing happened I had flashbacks to some horror movies I have watched, and about hurt myself jumping back so fast.

Anybody have any ideas?