You can clean calcium deposits off pool tiles with a hydrochloric acid solution and pumice stone. For light stain removal, any of the following cleaning supplies, along with a standard toothbrush, will work: Baking soda Toothpaste Vinegar Dish soap Calcium deposits usually result from an imbalance between the calcium levels and the pH of your pool. Maintaining your water chemistry at the appropriate levels is the best way to avoid excess calcium buildup.