Where we mention Clorox Pool & Spa Swimming Pool Calcium Hardness Increaser, 5 lb

• Calcium Hardness in Pool Water: What It Is, Ideal Range, and How to Adjust It

  Small calcium chloride pack · Best for: A limited correction or smaller pool that doesn't need a bulk sack

• Pool Eye and Skin Irritation: Causes and Water-Chemistry Fixes

  Best calcium increaser · Best for: Calcium chloride for raising low hardness.