Algae, Bacteria and Related Compounds Glossary of Terms


Microscopic plant-like organisms. Algae are nourished by carbon dioxide (CO2) and Phosphates and use sunlight to carry out photosynthesis. Algae are introduced by rain or wind and grow in colonies producing nuisance masses. Algae are not disease-causing, but can harbour bacteria. The most common pool types are black, blue-green, green and mustard (yellow).Maintaining proper sanitizer levels, shocking and super chlorination will help prevent its occurrence. A good quality algaecide should be used to prevent algae growth. A key source of food for Algae is Phosphates so reducing Phosphates in swimming pool water will also help prevent Algae growth.


A natural or synthetic chemical designed to kill, destroy or control algae. Can be copper based or copper free.


Introduced into the water by swimmers as waste, usually through perspiration or urine but can also be by other means. Quickly forms foul-smelling chloramines – a disabled, less effective form of chlorine. See chloramines or combined chlorine.

Shock dosing and super chlorination will help prevent Chloramines forming.


Single-celled microorganisms of various forms, some of which are undesirable or potentially disease-causing. Bacteria are controlled by chlorine, bromine or other sanitizing and disinfecting agents.


By-products formed when bromine reacts with swimmer waste (perspiration or urine), nitrogen or fertilizer. Bromamines are active disinfectants and do not smell, although high levels are irritating to the body. Bromamines are removed by super chlorination or shock treating.


A common name for a chemical compound containing bromine that is used as a disinfectant to destroy bacteria and algae in swimming pools and spas. Available mostly as a tablet or less often as a granule.


Undesirable, foul-smelling, body-irritating compounds formed when insufficient levels of free available chlorine react with ammonia and other nitrogen-containing compounds (swimmer and bather waste, fertilizer, perspiration, urine, etc.). Chloramines are still disinfectants, but they are a much weaker, ineffective form of chlorine. Chloramines are removed by super chlorination or shock treating.


This is a term that implies that an over-abundance of cyanuric acid (stablizer or conditioner) in the water would cause the chlorine to be all “locked up.” This is not true.