Quote Originally Posted by BigDave View Post
Do you have stains or other issues from the copper? Anybody's hair turn green? If it's not a problem, why fix it?
5 ppm is way too high and if it is not a problem now it will be. Does the pool have a heater? Heat exchangers are often a source of copper when the pool is improperly maintained and the pH drops too low. My guess is that the pool had been kept on trichlor tabs and the pH and TA was not monitored and the pH had crashed for an extended period of time. Copper levels should ideally be 0 ppm and anything above about .5 ppm can cause problems. When copper is used as an additive for algae control (not a good idea) added from an ionizer the upper limit considered acceptable is 1 ppm and even that will cause staining and other problems.