Metal Stains and Mineral Scale in Your Pool

One thing everyone agrees on when it comes to their pools is the desire for crystal-clear water and stain-free plaster. The causes of pool stains primarily fall in two categories: Organic and Inorganic. Organic problems such as algae and bacteria can discolor the water and deposit themselves on pool surfaces in a rainbow of colors. Other organic materials such as leaves, worms, or other vegetable matter can also stain pool plaster. Inorganic materials like copper, iron, magnesium, calcium or aluminum can also cloud or discolor the pool water and stain or scale the pool surfaces, especially the plaster and tile grout. When these minerals quit floating around and decide to attach themselves on interior pool surfaces, they form a whitish crystallized deposit known as scale. If the precipitated minerals have color, as heavy metals often do, they will deposit themselves in the form of a stain. A stain inhibitor, or sequestrant, will help with stains, especially inorganic stain prevention. At Atlantis Pools we add a stain inhibitor to our customer’s pools at least once a year. It is mainly for metal stain prevention. Your pool service should be adding a stain inhibitor at least once a year. Sequestrants are notable for their minimal metal staining properties, however most of them come with Phosphates that feeds algae growth. There is at least one company that has a zero-phosphate stain inhibitor. Next month we will talk more about scale. Meanwhile, please keep all non-pool toys out of the water. Things like bobby pins, paper clips and nails can create a lot of stains if they start bouncing around in your pool.