What chemical can be added to swimming pool water to raise the pH level?

Soda Ash, also known as sodium carbonate, is used in swimming pools primarily to increase the pH level of the water. When the pH of pool water is low (acidic), it can lead to issues such as corrosion of equipment and surfaces, skin irritation, and ineffective chlorine sanitation. Adding Soda Ash raises the pH levels back into the optimal range, typically between 7.2 and 7.8.

This adjustment is crucial for maintaining balanced water chemistry, ensuring swimmer comfort, and prolonging the lifespan of the pool equipment. Additionally, Soda Ash can also help to increase the total alkalinity of the water, which serves as a buffer for the pH, making it less likely to fluctuate significantly.

In contrast, other choices listed do not serve the same function. Bromine is primarily used as a disinfectant and sanitizer for pool water. Sodium chloride is used in saltwater pools for the generation of chlorine but has no effect on pH levels. Muriatic acid is an acid that is used to lower the pH level, not raise it. Thus, Soda Ash is the appropriate chemical for the purpose of increasing the pH balance in swimming pool water.