What to Use to Clean Dark Stains From a Vinyl Pool Liner

Types of Staining

• The most common forms of liner staining are caused by algae, mold or mildew. These are most commonly seen as dull black stains on your pool liner. Mold and mildew can be easily removed with bleach, but black algae staining is difficult and at time impossible to remove from the pool liner. Other stains are the result of organic waste such as pool leaves, dirt, and pollen which can stain a liner at the water line if left untreated.

Shock

• Depending on the type of stains they may be removed by shocking your swimming pool. The process of shocking your pool introduces pool sanitizer to the water. This can eliminate or loosen many dark stains on the pool bottom and on the sides near the water level. The amount of shock you put into the pool water will depend on your water capacity. After you add the shock let the filter run continuously for 24 hours.

Brush

• The type of stain on the liner calls for different remedies. Dark stains from algae can be removed by shocking followed by brushing. Many times the shock will loosen or kill bacteria on the pool walls and bottom. Use a nylon pool brush that can be purchased at your local pool supply retailer. Brush the areas of the pool that are stained. If you are removing algae stains, you may have to repeat and shock several times before the stains fade away completely. That's because before algae is killed it multiplies on a surface quickly.

Bleach/White Vinegar

• The most common pool liner stains are near the water line of the pool. Drain the pool, lowering the water several inches below the stained water line to allow adequate room to clean it. Make a solution of 1/4 vinegar, 1/4 bleach and 1/2 hot water in a spray bottle. Saturate the stained water line and let it soak for a few minutes. Take a cloth or a nylon scrub brush and wipe away the liner stains. The longer the stains were left untreated on the liner, the harder it will be to remove them. Some stains such as those from organic waste left sitting too long can permanently stain a liner. The best defense against pool liner staining is regular maintenance and cleaning.