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

Gas chlorine actually lowers the pH of water when it is introduced. This occurs because gas chlorine (chlorine in a gaseous form) reacts with water to form hydrochloric acid (HCl) and hypochlorous acid (HClO), both of which are acids. The introduction of these acids into the water results in a decrease in pH, making the water more acidic.

Understanding the chemical processes involved helps to clarify that the correct understanding of gas chlorine’s effect is essential for maintaining proper water chemistry in pools. Proper water balance is crucial to prevent corrosive conditions that could damage pool equipment and surfaces, as well as to ensure swimmer safety and comfort. It’s also important to note that balancing the pH is an ongoing process and additional adjustments may be needed if chlorine gas is used as a sanitizing agent.