We recently received a question about copper plumbing having a greenish tint from 'Sue', who asked...

"Hi....I am so confused as to which test to order. We have copper piping that has developed leaks due to tiny pin holes in the piping. Our PH is excellent but do not know what is causing the greenish color inside the pipes. Our plumber, about whom you can have a peek here, recommended we do a test on the water but since the water has normal acidity we do not know what to do now. Please help. Thanks so much. I am clueless and hoping you can point me in the right direction as to what we need to test for now!"

Hello, Sue, and thank you for your inquiry.  We suspect the greenish color you see comes from oxidation of the copper on its surface and the fact that you see it on the inside of the pipes indicates that your pipes most likely spent some time with air in them.  Perhaps the leaks in the pipes allowed oxygen into the system or maybe the system spent some time in a drained condition?

As for what caused the pinholes in the first place, pH would normally top the list as likely offender. Aside from that, you may want to take a look at alkalinity which affects the stability of the pH. If you have low alkalinity your water may have a great pH today and an absolutely horrible pH tomorrow.

Also, how old is the plumbing in question?  Perhaps just the age of the system has given it time to develop pinhole leaks?

Easy Way to Test for pH & Alkalinity

We currently carry a product called the WaterWorks pH & Alkalinity which performs a test for both pH and total alkalinity at the same time.

The WaterWorks pH & Total Alkalinity test strip utilizes a single test strip designed with two separate test pads: one for measuring pH and the other for measuring Total Alkalinity. The test procedure works well as an alternative to traditional wet chemical tests that sometimes require the use of potentially hazardous chemicals.

  • pH: 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0
  • Total Alkalinity: 0, 80, 120, 180, 240, 360 ppm (mg/L)

pH & Total Alkalinity Test Strips