I have couple of questions to the experts. I see copper stains (green/blue) in my sinks and at shower tubs. I had comprehensive water analysis done. Water was sampled from tap after flushing. My water is soft with pH 6.65. I am on well water. Below are the levels of some elements:

  • Hardness (calc.)->50.5 mg.CalCO3/L
  • Calcium-> 16.0 mg/L
  • Magnesium-> 2.56 mg/L
  • Sodium-> 10.0 mg/mL
  • Copper-> 0.221 mg/L
  • pH 6.65

Assuming that stain is coming from copper pipes, I called a company which installs filters.

The company told me that amount of stain is too much for the level of pH. I am not sure what to make of it. Could there be any other reason besides low pH to corrode my copper pipes. My house is 27 years old. I only had it for 3 years. And this house never had filtration system before.

The company proposed that I install neutralizer to bring pH to 7.0. This part makes sense to me and requires installation of a tank (tank #1). However, they want to install a water softener to remove neutralizer (Calcite) from water to make it soft again (tank #2). To regenerate softener matrix, they need a third tank (tank #3) for backwashing that uses salt for regeneration. Their calculation is that I (two people) would use ~500 pounds of salt per year for regeneration process. I personally think that it is a waste, and not an environmentally friendly method.

Moreover, my google search tells me that there many companies suggesting that if my water pH is above 6.0, I should only need neutralizer, not additional softerner/baskwashing tanks.

I am wondering if anyone has comments on this. Thank you very much.

  • pH and hardness of your water may change over the course of a year. Mine certainly does. Perhaps yours gets down low enough to liberate some copper. Commented Feb 17, 2018 at 19:44

2 Answers 2


This may not be much help or have anything to do with your installation, but I was told this by a large water heater tank company 30+ years ago. "Very Soft water heated close to and above 140 degrees F. becomes very aggressive and has very detrimental effects on metals it comes in contact with". I do not know if this is true or not, that is what I was told. The next time you speak with someone in the water field, you could ask their opinion and could this be a part of your problem. Also, water with a PH below 7.0 becomes corrosive. I am not a water expert, this just what I have been told.


According to this link, you should need a water softener if the water hardness is greater than 170 mg/l before adding the neutralizer. Your test shows a much lower value - 50 mg/l. If it was me, I’d put in the neutralizer, and leave room for the softener just in case - it can always be added later.

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