Copper pipes dirty inside

Old 01-29-16, 06:18 PM
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Copper pipes dirty inside

I have been replacing Cu with PEX and what I was really surprised to note is that the pipes in my place have some pretty nasty residue.
I noted clear signs of oxidation / rust (greenish / redish deposit on the inside).
Always thought Copper to be very inert metal and though that pipes on the inside stay relatively "like new"
IS this a indication that my water is particularly "harsh" or is that normal to notice with pipes from 1950s ?


PS: All the appliances, water outlets, heating units etc.. always look good and the only issue I have with my water is mild hardness.... visible on crystal and glass after washing in a dishwasher (if not using Jet Dry).
Old 01-29-16, 07:01 PM
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Copper is a mineral/metal and there are also naturally occurring minerals/metals like manganese, iron, magnesium, etc... in your water. Its the residue from the minerals that you are seeing. Probably the same color (or worse) in the back of your porcelain toilet tank.
Old 01-30-16, 04:17 AM
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There are some areas of my county where the well water is very corrosive. Dripping faucets leave green stains and copper pipes are eaten from the inside out. In those areas the inside of the pipes are surprisingly clean looking. If you are seeing mineral deposits inside your pipes it might indicate that your water is slightly hard (contains dissolved minerals). If it were unusually high you probably would have noticed problems like soap doesn't suds up properly, shower heads acccrue visible mineral buildups and dishes get bad water spots.
Old 01-30-16, 04:49 AM
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We are on our municipal water supply and last time I replaced my electric warer heater the inside of those pipes near the heater were nasty black. It wasn't a good time to be investigating as I suspected the entire system would look the same. Sure would like to know if pex would solve the condition as most of my copper is readily accessible. Back when copper prices went crazy I probably could have paid for the conversion with the copper. Not now.


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