Accuracy of swimming pool test kits

Abstract

Background: Pool Chemistry is important to allow those using it to feel comfortable through pool water being physically clean and biologically safe. Operators and health inspectors use test kits to ensure that pool water chemistry is correct and will not cause irritation or problems to both the patrons and the pool recirculation system. This study investigates the accuracy of the three commonly used pool test kits available in the market (Taylor, HACH, and ColorQ). Parameters tested are Free Available Chlorine (FAC), Total Chlorine (TC), and pH. Methods: Using artificial pool water with known concentrations of FAC, TC, and pH, 30 samples were taken for the three different parameter from the three test kits. The indicated concentrations and pH on the test kits were then recorded and used to compare with the known standards. Results were analyzed using the statistical software NCSS. One sample t-tests were performed to indicate whether or not the test kit as accurate in reading different parameters of pool chemistry. Results: Taylor Test Kit: Readings for FAC (2.6ppm) showed 2.4ppm, TC (2.7ppm) showed 2.43ppm, and pH (7.1) showed 7.1. HACH Test Kit: Readings for FAC (2.8ppm) showed 3.5ppm, TC (3.0ppm) showed 3.5ppm, and pH (7.1) showed 6.97. ColorQ Test Kit: Readings for FAC (2.7ppm) showed 3.0ppm, TC (3.0ppm) showed 3.0ppm, and pH (7.0) showed 6.96. Conclusion: All three test kits have accurate readings for pH levels. However, the test kits do not provide accurate readings for FAC and TC which would make it difficult to calculate CC in pool waters. Although the FAC and TC readings are inaccurate, they are able to provide operators and health inspectors with brief information regarding pool water chemistry.