Calcium usually enters your pool through your tap water or those fancy calcium-hypochlorite shock treatments. It’s like when you accidentally pour too much salt into a soup—there’s no taking it back once it’s in there. The culprit is hard water, same stuff that leaves white spots on your shower glass and makes your soap sud up like a cartoon bubble bath.
Let me tell you a little story. Last summer, my neighbor Bob filled his pool with well water because he was in a hurry. Two weeks later, his pool looked like a swimming hole in a limestone quarry. He spent a whole Saturday scrubbing the walls with a brush and cussing at his hose. Don’t be Bob. Check your water hardness first.
