For all the plumbing experts out there I am having a persistent problem with a some copper pipe leaking. After reparing the pipe several times i finally just replaced the whole run and in examining the pipe I noticed some type of growth inside the pipe. It was only the one piece that was leaking and in examining the inside of the pipe there are lots of small deposits growing inside that I believe was causing the pin hole leaks. It is a hot water line and i have a solar heating system. i have had no problem with any of the other pipes in the house. The house is about 24 yrs old. Has anyone ever seen this type of situation before and if so what is it.