Blue Green Stains

Diagnosing your stain part 3

The Blue Stain – Most stains are the yellow orange variety that we’ve discussed previously. Just as common are the white spots and build-up caused by hardness or very commonly, silica. But what about the blue or green  staining you get on fixtures?


Blue stains, what are they?

With your typical (non-blue/green) stain, the cause is often as simple as what’s in the water: minerals, sediment, and even treatment chemicals can stain, either on their own or through interaction with the pipes and fittings. These stains, although harmless, can be annoying and difficult to clean.

Blue or green staining occurs with copper pipes and fittings and is caused by the corrosion of the metal itself. When the copper-laden water is allowed to sit, it stains. Since the staining is caused from the pipe itself dissolving, it can have a negative impact on the taste of the water as well. Most people would describe this as a “metallic” taste.

How does it happen?

The excessive corrosion that leads to copper staining is most often caused by acidic water. Acidic water can be described as water that has a PH of <7. The dissolution of copper really begins at a PH of about 6.8 and is further enhanced when the water supply is high in dissolved oxygen, carbon dioxide, and other gases. When the acidic water flows through the copper pipes small amounts of the metal are eaten away and dissolve into the water. Since we don’t often dry off our fixtures after use, the water sits and eventually stains occur on the surfaces.

Symptoms of acidic water:

  • Blue or green stains on showers, sinks, and other plumbing fixtures
  • Green soap scum or curdy precipitate
  • Unpleasant metallic or medicinal tastes
  • Corrosion of aluminum fixtures

Stopping the problem:

In low levels, copper is not usually considered harmful to humans, but higher concentrations can result in the unwanted side effects listed above. By using a calcium media, common treatment methods can add hardness to the water. This method raises low ph but may require additional treatment to combat the added hardness. Water softeners can remove moderate amounts of copper but the best way to treat a copper staining issue, is to eliminate the corrosion problem. The ICS (Integrated Cartridge Solution) system offers a product called PolyHalt® that does just that. PolyHalt® is a polyphosphate that can help to protect plumbing from the effects of corrosion, silica, and other minerals such as iron and manganese. By adding a thin protective coating between the metals and the water, low ph water is not able to to dissolve or react with the metals it comes in contact with. This solves the problem of low ph without adding hardness minerals. For more information about ICS and PolyHalt® please visit our website at


Jodi Larsen
Jodi Larsen joined the Cascadian team in 2017. Jodi is new to the water treatment industry but is eager to learn and assist our customers in any way possible. Jodi grew up on the westside of the state and graduated from Puyallup high school. She moved to the Cle Elum area in 1998 where she has worked in a variety of jobs. She has an extensive background in customer service and feels that people truly are her strong suit. She enjoys working with customers, helping to define a problem, and collectively finding the best solution. When she’s not at work Jodi is very active in our local Rotary Club where she advises our Interact club. Interact is a youth-based community service club comprised of students from 6th to 12th grade. She has taken kids on several international trips to developing countries where they focus on clean water, sustainability, and educational opportunities. She is also a long-time board member for ARRF Animal rescue, was recently elected to The Kittitas County Chamber of Commerce board and has served on our local City Council. She truly enjoys being part of the solution both professionally and personally. We are happy to have her on our team and know that you will be well cared for should you need anything.