Certified Pool Operator Test 2025 – 400 Free Practice Questions to Pass the Exam

The chemical commonly used to raise the pH of pool water is sodium carbonate. Sodium carbonate, often referred to as soda ash, is effective in increasing the pH levels because it is alkaline in nature. When added to pool water, it reacts with the water to produce hydroxide ions, which increases the pH.

While calcium chloride and sodium bicarbonate play important roles in pool chemistry, their primary functions differ from that of a pH increaser. Calcium chloride is mainly used to increase calcium hardness in the water, while sodium bicarbonate is used primarily to raise total alkalinity, which in turn can help buffer pH fluctuations but does not directly raise pH as effectively as sodium carbonate. Sodium hypochlorite, on the other hand, is a chlorinating agent used for sanitation and has minimal effect on pH levels, typically causing a decrease in pH rather than an increase. Thus, sodium carbonate is the most suitable choice for raising the pH of pool water.