First time owning a pool. We have a 12" raised spa, and on the side of the circle spa that faces the pool the explosed tile seems to have built up some hardended calcium spots. I think it's calcium. It's white colored, only occurring on the tiles that are on the raised spa. The white built up is "crystalized" not flat on the tile.
Any ideas or recommendations on how to get this cleaned up. Don't have any pictures of it right now but can post some later.