How do I raise calcium hardness in my pool?

Dissolve pool-grade calcium chloride (not road salt) in a bucket of water and pour it evenly around the pool edges while the pump runs. Follow the dosage on the bag based on your pool size and current hardness level. Don’t use calcium hypochlorite unless you also need to raise chlorine, and don’t dump it in one spot to avoid clouding or staining. Test first — most pools need 200–400 ppm, and if you’re below 150, you need it; if just slightly low, skip it unless you have a plaster pool or old liner.