Why does your pool liner turn green in spots?

* Algae growth: Algae is a plant that can grow in swimming pools, especially if the water is not properly treated. Algae can be green, black, or brown, and it can form on the pool liner, walls, and steps.

* Metal stains: Metal stains can occur if the pool water contains high levels of metals, such as iron or copper. These metals can react with the chemicals in the pool water and form a greenish-brown stain on the pool liner.

* Organic matter: Organic matter, such as leaves, grass, and dirt, can also cause the pool liner to turn green. When organic matter decomposes, it releases chemicals that can react with the pool water and form a greenish-brown stain.

To prevent your pool liner from turning green, it is important to:

* Keep the pool water clean and free of algae: This can be done by regularly testing the pool water and adding chemicals as needed.

* Remove metal stains: Metal stains can be removed by using a metal stain remover.

* Prevent organic matter from entering the pool: This can be done by covering the pool when it is not in use and by regularly cleaning the pool filter.