Will the salt water damage the copper pipes in an old pool?

You've got to be kidding with that answer!?!? You have no business in a room where water chemistry is being talked about. 7.0 pH is neutral pH. It won't hurt anything.

On the other hand, the ASM Handbook points out that high TDS water through a heat exchanger will result in impingement and erosion corrosion, which is why all the heat exchangers have started failing since salt systems came along. It's probably the reason that somebody asked this question. And why pool heater warranties have plummeted from 5 years to 1 year since about 2004. What I coincidence! Huh? Imagine that...

Here's a link to the ASM Handbook where you can read all about these kinds of corrosion:

google.com/books?id=idIWxNnH3iIC&pg=PA999&lpg=PA999&dq=impingement+corrosion&source=bl&ots=7ubxPY3a9C&sig=FPg0JS9xZm-qCPsGmPaEpRN8sTk&hl=en&ei=CIWySc_AJYmcMv25qecE&sa=X&oi=book_result&resnum=10&ct=result#PPA998,M1">http://books.google.com/books?id=idIWxNnH3iIC&pg=PA999&lpg=PA999&dq=impingement+corrosion&source=bl&ots=7ubxPY3a9C&sig=FPg0JS9xZm-qCPsGmPaEpRN8sTk&hl=en&ei=CIWySc_AJYmcMv25qecE&sa=X&oi=book_result&resnum=10&ct=result#PPA998,M1

AnswerSalt water should not have any major effects on your pool Plumbing since the levels of salt are so minimal. The damaging effects to copper plumbing would be from acidic conditions - pH readings of 7.0 or lower and total alkalinity readings below 80 ppm.

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