jaygreg wrote:
Here's how I led to the speculation:

1) White mineral deposits formed at end of faucet nozzles (lightly but
enough to find material in the screen filters... usually
white...assumed calcium)

2) Water pressure noticeably lower. Neighbors notice no change in
their pressure.

First, regarding your original post -- I think that is an interesting idea
although I really don't know whether it would work or not etc.

But, since you said that you have all copper plumbing, as others have
said -- it doesn't appear that corrosion would be the reason for a lower
water pressure/flow.

Since you wrote earlier that you are finding the low flow problem "in
selected pipes", it may just be that dirt and particles of debris are
clogging the faucet aerator screens etc. If you did any plumbing work
(repairing valves etc.), pieces of dirt and debris can break loose and clog
the screens. Happens all the time. The same could be true if the town did
some work on water lines outside of your house.

Another possibility could be a valve which has a rubber washer that is
broken or damaged or came off from the valve stem. If that happens, opening
the valve can still leave the washer stuck in the valve in a position where
it restricts the water flow. This could be in a main water valve or another
valve somewhere else. You would have to take the valve stem off and look to
be sure.