Which chemical is used to increase Calcium Hardness?

Flake calcium chloride is the correct choice for increasing Calcium Hardness in swimming pool water. Calcium Hardness refers to the concentration of calcium ions in the water, which is essential for maintaining water balance and preventing corrosive conditions that can damage pool surfaces and equipment.

Flake calcium chloride is a calcium compound that dissolves in water to release calcium ions, thus raising the hardness level. Ensuring proper Calcium Hardness helps to protect the integrity of the pool structure and the effectiveness of sanitizers.

The other chemicals listed serve different purposes. Sodium bicarbonate is primarily used to increase alkalinity, not Calcium Hardness. Muriatic acid is utilized to lower pH levels, while calcium hypochlorite is a chlorine compound used for sanitization but does not significantly affect Calcium Hardness in the same manner as flake calcium chloride. Understanding these roles is crucial for effective pool maintenance and chemical management.