How to Treat Black Spots on Pool Liners
- 1). Lower the level of water in the pool only if the black spots are underwater. Don't fully drain the pool, however, as this could cause the pool to collapse and vinyl liners to dry out and crack. When lowering the water level, work fast so you can refill the pool to normal levels. Drain water with a sump pump or the pump built into the pool.
- 2). Mix water with distilled white vinegar into a bucket at a ratio of 1 cup per gallon. The acid in the vinegar acts as a bleaching agent to help kill the mold. Avoid using harsh chemicals such as bleach, which can damage the vinyl liner.
- 3). Wet a nylon bristle brush with the vinegar solution and scrub the black spots with the brush until you remove all of the mold. Black mold can permanently stain vinyl liners. You will know the mold is gone when the surface of the liner is flat and the black spots are not bumpy.
- 4). Rinse the area clean with the vinegar solution and a soft sponge.
- 5). Restore the pool to normal water levels, using the garden hose.