Swimming pool water needs regular cleaning and disinfection because repeated use makes it vulnerable to contamination. Pools are found in homes, hotels, sports clubs and resorts, in different shapes and sizes. Treatment involves several steps to keep the water clean, disinfected and free from disease-causing microorganisms, and to maintain an acceptable smell, using appropriate chemicals and other methods.
Pool water undergoes continuing chemical changes. Its temperature can provide conditions for bacteria and algae to grow. Water therefore needs regular sampling and testing to maintain cleanliness, pH and hardness, since changes can affect bathers, particularly their eyes.
Pool treatment methods
Filtration
Dedicated pool filters remove algae, solids and dirt from the water.
Disinfectants
Disinfectants and chlorine are commonly used to treat pool water. Chlorine comes in tablet, granular or liquid form. These products disinfect against germs and bacteria and help prevent algae.
Water acidity balance — original historical wording
The original article recommends first measuring pH, the acidity or alkalinity of the water, and keeping it between 7.2 and 7.8. It states that lower readings can corrode the pool finish, while higher readings can cause cloudy water, reduce chlorine effectiveness and clog filters.
It then states that cyanuric acid is added to maintain alkalinity, sodium bicarbonate or soda ash is added to raise the acidity level, and disodium phosphate or muriatic acid lowers pH. It gives total alkalinity as 90–150 ppm. These statements are preserved as the original article's wording; see the correction above before considering any chemical treatment.
Water hardness
The article attributes hardness to calcium and recommends replacing old water with fresh water when calcium is high, to maintain water clarity.
Chemical treatment
Chemical treatment addresses unpleasant odors and microorganisms.