Why is My Bath Water Green? Causes & Fixes

If your bath water is green, chances are you have serious complications with your water quality. When not solved, this problem can worsen with time. If your bath water has an impression rather than clear, you should hesitate to take a bath in it.

When your water is bluish or greenish in color, it’s due to the presence of copper. This copper comes from corroded pipes, polluted water, limescale, and mold or mildew. Copper is removed from the water through ion exchange filters, distillation, reverse osmosis, and flushing of the plumbing system.

If you notice a blue or green color in your drinking water, you should avoid taking it and, instead, call a plumbing expert right away. This post will give you helpful information about the leading causes of green or blue water in your bath and possible fixes. Read on!

Greenish-blue bath water

Why is My Bath Water Green?

Here are common reasons why your bath water has a green or blue color:

1. Polluted Water

High levels of copper and other pollutants in your water source can give your bath water a green or blue color. Typically, copper pollution occurs when water passes across the pipes or may even come from the water source.

Most plumbing systems are installed with copper pipes which wear down after some time. Copper can also accumulate in your private well. Water contaminated with copper will have a metallic taste or odor.

2. Rusted Piping

Over 75% of plumbing systems use galvanized steel or copper pipes. Although these pipes are effective for passing water, they easily degrade after some time. Metals break down faster than required through electrolysis, giving the water a blue or green color.

Typically, the rate of electrolysis accelerates if you have a corrosive or contaminated water source or aged plumbing. Corroded plumbing, including copper sinks, gives similar symptoms to contaminated water, and each can become the cause of the other.

3. Buildup of Limescale

Most bathrooms suffer from limescale problems. Using hard water leads to the deposit of minerals that form limescale. You can easily find limescale around your faucet and above the tiles. 

Limescale appears white, but when it blends with copper from the plumbing system, it can lead to green or blue bath water.

You can easily detect the limescale buildup in your bathroom. Limescale within or around your faucet can likely cause water discoloration. Although limescale is not a common cause of green water in the bath, it can be a possible cause.

4. Mildew or Mold

Mildew and mold can cause a green color in your bath and possible health problems. Additionally, mildew and mold can come in multiple colors, including green, blue, white, black, blue, and green. Mold can also grow on many different surfaces, including concrete.

Although less common, mold buildup close to your wall or basement can transfer into your water supply, turning it green or blue. This accumulation can subject you to serious health issues.

How Does Copper Get into Your Home’s Water?

Although you can easily find small portions of copper in rivers and lakes, copper from water sources is not the primary source of contamination. Instead, the main source of copper in tap water is the corrosion of copper pipes.

Most plumbing systems have copper pipes. If your tap water has corrosives, they can quickly wear out the copper pipes over time and dissolve traces of copper into your water. 

The main cause of corrosive tap water is acidic water (low pH levels). However, contaminants such as zinc and chloramine can also wear out your pipes. That said, copper in tap water results from corrosive water.

What Type of Water Pipes Do I Have?

The following are the most common pipes you can easily find in your plumbing system:

1. Copper Pipes

Copper pipes have been commonly used in the plumbing sector for many years. These plumbing pipes can last for 50 years and are widely used in tubs, showers, sinks, and other fixtures in vintage and modern homes. Most plumbers prefer copper pipes due to their high temperature and pressure change tolerance.

2. Galvanized Steel Pipes and Cast Iron

Galvanized steel and cast iron pipes are rarely found in modern homes and are commonly found in buildings constructed in the 20th century. These pipes are highly durable and are mainly used for water distribution and other drainage purposes. However, they are highly prone to corrosion and rust.

3. PVC Pipes

You can easily find PVC pipes in your shower drain line, toilet, and sink. These piping are ideal since they prevent water from catching corrosion and rust. They are highly durable and can last indefinitely unless subjected to some damage.

4. PEX Pipes

Cross-linked polyethylene or PEX piping refers to an affordable plastic tubing mainly used in water supply lines. These pipes almost resemble PVC piping and are highly resistant to corrosion and rust. 

Experts prefer these pipes due to their flexibility and ease of weaving through ceilings, walls, crawl spaces, and basements.

Does My Water Have Too Much Copper?

Color change in your water can signal high amounts of copper. In addition, excessive corrosion can trigger pinhole leaks in the piping system, indicating an excess amount of copper.

However, you can quickly determine the copper levels in your water using a copper testing kit that produces accurate results within minutes.

If the copper level is about 1.3 mg per liter and above, it is best to address it, as it may necessitate the installation of new plumbing or pipe fixtures. A professional plumber can help you to remedy this problem.

Symptoms of Copper Absorption

Copper absorption into your body by ingestion or bathing can be bad for your health. Small amounts of copper in your water are okay to bathe in, but you should evaluate their levels. 

Signs that you may experience due to high copper levels include:

  • Diarrhea
  • Vomiting
  • Nausea
  • Possible kidney or liver disease risk

These aren’t issues to overlook and need to be addressed fast.

Too Much Copper in the Water: Fixes

The main effective methods of removing copper from water include ion exchange, distillation, and reverse osmosis. It is essential to know that boiling water will increase the amount of copper concentration. In addition, chlorine disinfection cannot remove copper from the water.

1. Ion Exchange Filters

Ion exchange filters convert copper ions into hydroxyl and hydrogen ions. The hydrogen ions are placed in resin beds where unfiltered water passes through. 

In addition to removing copper ions, these filters also minimize water hardness by eliminating minerals such as magnesium and calcium. However, this method has the drawback of requiring regular replacement since these filters are easily clogged with waste and impurities.

2. Distillation

Distillation removes copper traces by boiling. Typically, unfiltered water releases vapor, condensing into pure water and leaving behind impurities. This method effectively removes copper and other impurities from the water. However, it is time and energy-consuming and less ideal for home use.

3. Reverse Osmosis

Reverse osmosis is a water filtration approach that works by passing contaminated water through a semipermeable membrane under high pressure. 

The membrane has tiny holes of about 0.00001 microns, which is small enough to allow only water molecules, blocking impurities such as copper. 

This method is among the most effective water filtration systems for home use. It is usually placed beneath the kitchen sink to generate clean water through a separate faucet.

4. Flushing the Plumbing System

You can also eliminate traces of copper from your system by flushing. This method involves allowing water to run through a faucet that has been dormant for more than 6 hours until the water acquires an excellent appearance. 

If this method is ineffective, consider the water treatment options discussed earlier.


The water in your bath can appear green or blue due to high levels of copper or rust, mold, and limescale buildup. This can cause severe problems to your plumbing system and your overall well-being. 

Thankfully, I have discussed multiple effective water treatment options to save you from such risks. If you’re unable to carry out the above methods, consult an expert in your area for help.

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