What chemical is commonly used to raise the pH level in pool water?

Sodium carbonate, commonly referred to as soda ash, is the chemical used to raise the pH level in pool water. When pool water becomes too acidic, a higher pH level is needed to create a balanced environment that is safe for swimmers and effective for chlorine sanitization. Sodium carbonate increases the alkalinity and helps to stabilize pH levels, making it an essential chemical for maintaining optimal water quality in swimming pools.

In contrast, calcium chloride is primarily used for increasing calcium hardness in water, while hydrochloric acid is utilized to lower pH levels. Potassium sulfate serves as a source of potassium and sulfate ions but does not influence pH in the manner required to correct low pH levels. Thus, sodium carbonate is the appropriate choice for effectively raising the pH in pool water.