We recently moved into a 15 year old house in a very hard water area serviced by well water, and recently had a pinhole leak in a hot water pipe in our finished basement ceiling. We had it fixed but now have serious doubts about the quality and lifespan of our copper piping. We have lately been seeing a blue tint to the water on occasion, which indicates copper seeping into the water. This leads me to believe the pipes are still deteriorating, and the PH level is pretty much beyond my control (I'm told by our water department that it varies between 6.8-7.0). It would be a MAJOR project to replace all of the piping as our basement is completely finished with drywall ceilings, and the pipes in the rest of the house would be equally difficult to get at, but I cant imagine the damage if one of the pipes on the second floor were to start leaking.
Repair as necessary?