Which chemical is commonly used to raise pH levels in a pool?

Sodium carbonate, commonly known as soda ash, is frequently used to raise the pH levels in a swimming pool. When pH levels fall below the ideal range (7.2 to 7.8), it can lead to corrosive water that can damage pool equipment and surfaces, as well as irritate swimmers' eyes and skin. Soda ash effectively increases pH due to its alkaline nature.

When added to pool water, soda ash dissolves and releases carbonate ions, which react with hydrogen ions in the water to increase the pH. This chemical also possesses the added benefit of contributing to alkalinity, which is important for stabilizing pH levels over time.

Other substances may serve different purposes: calcium chloride is primarily used for increasing calcium hardness, sodium bicarbonate is used mainly to raise total alkalinity, and potassium permanganate is typically utilized as an oxidizer and disinfectant rather than for pH adjustment. Therefore, soda ash is the preferred choice for raising pH in pools.