Acids in swimming pools increase the acidity of pool water, and encourage corrosion of pool surfaces and equipment.
What is an acid?
Weak acids like lemon juice and citric acid are sour to the taste and are commonly associated with acids, but an acid is any substance that reacts with a basic substance. The desired pool water pH is 7.5 and slightly basic. Swimming pools with a pH of anything below 7.0 are considered acidic. The lower the pH, the more acidic the pool water is.
Acids readily release protons as hydrogen ions, creating hydronium, which is extremely acidic in water. Distilled water has roughly the same amount of hydroxide and hydronium ions. As water becomes more acidic, water more easily gives up its extra proton as hydronium is more active. The excess hydronium promotes the corrosion of metal surfaces in the pool, and is why it is bad to keep pool water acidic.
How are Acids used in swimming pools?