Swimming Pool Water Treatment


Swimming pool water treatment aims to:

1. Control the pH of the water so it is not irritating to the eyes of swimmers

2. Control bacteria and algae using biocides and algaecides or simply a cover to block the sun

3. Filter out suspended solids or hair/fibers/leaves so that the water is clear

4. Control the smell of chlorine if it is the used biocide

5. Control the chemical balance of the water so that it is neither scaling nor corrosive

6. Remove color causing compounds or elements from the water.


For pH control, various acids and alkalies are used such as Hydrochloric acid and soda ash.

For disinfection, various oxidizing and non-oxidizing biocides can be used as well as UV light disinfection. Even ultrasonic disinfection can be used such as Ashland's SONOXIDE technology.

Suspended solids can be filtered out using sand filtration, pre-coat filters which use diatomaceous eath, microfiltration or ultrafiltration. Ofcourse a pump of suitable size has to be selected so that the water turn over rate is sufficient depending on the use (adult versus children's versus baby pools).

A strong chorine smell could be indicative of overdosing of chlorine or of formation of chloramines which are formed from the reaction of ammonia with chlorine. To remedy this situation chlorination beyond the break point of chlorine is needed which means additional chlorine is addded to break down the chloramines.

For balancing the water, calcium rich compounds such as lime or calcium chloride can be added or carbonate rich compounds such as soda ash can be added. A scaling water will form scale in the pipes and on the fittings. A corrosive water will leach out the calium in the cement that glues the tiles together. It is also possible to use softeners in case of hard water.

Color causing compounds could be Natural Organic Matter such as humics or transition metal compounds such as ferric or manganese. These can be oxidized, or coagulated/filtered. It is also possible to use ion exchange for this.

See, It is really simple !



Rami E. Kremesti M.Sc.