Many people have a problem with blue/green stains on their plumbing fixtures and faucets. Most of the stains that are regularly encountered are caused by a contaminant that’s been dissolved into the water supply. But, blue or green stains are actually caused by the copper plumbing pipes and fittings that are installed in your home. Let’s take a closer look at the cause of these stains and how you can fix the problem.

Copper Corrosion Problems

The blue or green stains that appear on pipes and fitting is caused by the corrosion of the metal. When water that’s infused with copper is allowed to sit in one place for an extended period, it will become stained a blue/green color. The staining is a symptom of the copper pipe surface dissolving into the water. As well as creating unsightly stains that are hard to clean, it can also make the water unpalatable, and some would describe the taste as metallic.

How Does Copper Corrosion Occur?

The usual cause of copper corrosion and the accompanying blue/green staining problem is an acidic water supply. Water is classified as acidic if the pH level is less than 7 and dissolution of copper actually begins at a pH level of 6.8. This is exacerbated if the water supply contains elevated levels of carbon dioxide, dissolved oxygen, and certain other gases.

As the acidic water flows through your copper pipes, tiny quantities of the metal are corroded away, and then it dissolves into the water. Many people are unaware that water is an extremely effective solvent and given enough time it can dissolve a wide variety of materials. Because we don’t typically dry off every plumbing fixture after it’s been used, the water will sit there, and this will form blue/green stains on the surface of the fixture.

What are the Symptoms of Acidic Water?

There are four main symptoms of acidic water that you can identify; they are:

  • An unpleasant metallic taste in your drinking water.
  • Blue or green stains on sinks, tubs, showers and other plumbing fixtures.
  • Blue or green soap scum deposits.
  • Corrosion in aluminum fixtures.

How Can You Treat of Acidic Water?

When copper is present in low concentrations is not considered to be harmful to human health. But, acidic water will damage your copper plumbing pipes and fixtures leading to leaks and an expensive repair bill. So, how do you treat the acidic water to save this unnecessary wear and tear on your plumbing system?

Most common treatment methods use a calcium based media to raise the pH level, but this can add some hardness to the water. This additional water hardness can be removed by installing a water softener. Many water softeners can remove modest amounts of copper on their own, but this doesn’t address the underlying acidic water problem. There are products that add a thin coating of polyphosphate to the internal surfaces of copper pipes to protect them from reacting with acidic water that has a low pH level.

By EcoWater Systems.
EcoWater Systems of Nebraska is the largest water treatment company in the state and is a member of Water Quality Association.