Metal Contamination in Pool Water: How Does It Happen and What Can You Do?


Any pool operation involves three basic things: physical, biological and chemical factors. Under chemical factors, we are mainly talking about corrosion and scale formation. Many pool owners are unaware of these serious reactions until the pool starts turning unsightly, especially after shocking or the addition of chlorine.

Naturally, every water body contains various metals, with the numbers and levels depending on the type of water body. In the swimming pool, metals are perpetually present but in dissolved form. The problem escalates when the metals come out of their solution and cause an eyesore.

You should not worry about the health effects of these metals either, but the aesthetic impact is enough reason to find out more about the issue and combat it as soon as possible.

Entry of Metal in Swimming Pools

Since a new swimming pool in Salt Lake City does not have a metal infiltration problem, what causes the issue after that? Most pool water contains copper and iron, metals you will also find in municipal waters in Salt Lake City.

Conventional pool plumbing is a major source of these metals, but the deterioration of the water supply at any section can produce the same. The presence of cast iron headers and copper heat exchangers in the majority of pool heaters has also proved a serious challenge. Silver and copper algaecide products are other conventional sources of metal, as is the accidental entry of metals such as toys and hair clips.


Empty swimming pool

An iron solution is colourless, but since this metal reacts with chlorine and other chemicals in pool water, it exhibits a red discolouration. You only need a paltry 0.1 ppm of iron, and the pool will change its appearance. If tests show there is iron, but the pool still looks nice, there is no need for action. However, heavy staining calls for emptying, cleaning and acid washing of the pool.


Both algae and copper emerge as green colours in the pool. However, a slight difference is that copper forms a true clear green, while algae are cloudy green. When you enter your new swimming pool and your fingernails or hair turn green, you’ll know it’s copper. The best way to tackle copper in pool water is to add a chelating or sequestering product. However, you need to test the copper level alongside calcium hardness, total alkalinity, pH and chlorine to be sure they are at the recommended level.


Manganese can also affect pool appearance, creating a deep purple or pink discolouration. It only gets into the pool water via the source of water. The water treatment plant may add it to the water as potassium permanganate. Again, the metal is always present, but overdoses might cause problems. Like in the previous metal, a sequestering agent may remove or control it.

The fact that metals are in your pool is not a suggestion that we should give up taking a deep dive in the water. It is only meant to make owners more confident that they can solve the mess when all those discolourations appear.

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