The swimming pool service contractors from SwimRight Pool Service & Repair in Scottsdale, Arizona offer the answer to why does the pool have black stains to swimming pool owners. The black stains are typically caused when the water has chemicals present and when a swimming pool owner may not be as well-versed as he or she needs to be in order to prevent the staining from occurring.

When metals are present in the water, the possibility for staining is not far behind.

Why does the pool have black stains?

Metals in the swimming pool water need to be addressed as soon as possible. If the stains are left unaddressed, the staining may be permanent. Metals in the swimming pool can be prevented when your pool contractor adds a metal sequestering agent like a stain and scale preventer.

If you’re not certain what needs to be added, how much, or when the services of a professional pool contractor makes sense. Even if you clean and maintain your pool water and equipment yourself, you may still want to have the pool water tested monthly for metals by a pool professional.

When you test the water, using your water test kit, and see a reading that shows metal levels are .2 parts per million or above, a scale and stain preventer will need to be added at least weekly. Once you’ve noticed metals present in the water chemistry, you may want to shock the pool one week and add a scale and stain preventer the next until the metals are under control.

 Why does the pool have black stains?

When a metal sequestering agent is added to the water, it will help push any metals from the water and into the filter where they will then be removed. If you notice metals in the water, run the filter and pump for a continuous twenty four hour period to remove as many of the metals as possible.

A metal sequestering agent and running the pump and filter for an entire day will also help prevent scale and calcium formation on the pool walls.

Not all metals in the water lead to black stains. Copper will leave white/blue stains, iron will look like rust or will appear black, manganese appears a black stain.

Metals are naturally occuring in many water supplies. Metals occur when the metal fixtures and pipes erode and corrode. Adjusting the alkalinity and pH will also help keep metal problems at bay. If you see stained areas, remove the stains with a brush and cleaning agent that are correct for your pool construction material.

After you’ve identified, removed and begun treating the metal stains, it is important to be diligent and vigilant in testing for metals. In many cases, this type of water chemistry issue may require the services of a pool professional.