How to Remove Stains From a Plaster Swimming Pool
Apr 13, 2018· A small swimming pool stain is usually caused by a metal object being left on the plaster bottom long enough to rust and leave a stain. Most metals, when subjected to swimming pool water chemicals, will react and leave a stain where they were in contact with the pool's plaster.The most common objects to stain swimming pools are soda or beer cans, pop tops, and coins.