Here’s a little known fact about your swimming pool…one of the purposes of the tile line around the surface of the pool is to disguise the scum line or “bathtub ring” that would be visible due to the fluctuating water line (from bather load, evaporation, water level). Body oils and sunscreen tend to collect on the tile. This is most noticeable/prevalent in commercial pools because of the heavy swimmer load.
Over the years we’ve tried everything imaginable to efficiently clean the tiles. We discovered that Joy dish soap works the best (Dawn & generic dish soaps will also work). There is a degreasing agent in the soap and when you put a small amount on a sponge you can quickly clean the surface of the tiles. After your tile is clean (or already in good shape and not noticeably scummy) add four drops of Joy directly into your pool every month (15’ X 30’ std pool). This will keep your tiles from collecting the scum and it won’t effect your pool’s water chemistry. It will also extend the life of your pool filter if you use a cartridge filtering system.