Acid: A chemical which lowers pH when added to water.
Algae: Microscopic aquatic plant life which can grow on pool surfaces or float free in the water.
Base: A chemical which raises pH when added to water.
Bacteria: One celled organisms, some of which cause disease and/or infection. Without proper sanitation, pool water and pool surfaces are perfect breeding grounds for bacteria.
Calcium Hardness(CH): The quantity of calcium dissolved in the water.
Chlorine: The sanitizer and oxidizer most commonly used in swimming pools.
Organic Waste: Nitrogen and ammonia bearing compounds such as urine, saliva, perspiration, body oils and suntan lotions that are continuously introduced into pool water by swimmers. Most organic wastes will not filter out and must be chemically removed (oxidized) with a periodic shock treatment.
pH: The measurement of water's relative acidity and basicity. The pH range is from 0 - 14; a pH of 7 is neutral. pH values below 7 are acidic and values higher than 7 are basic. The recommended pH for pool water is 7.2 to 7.8.
Residual: The amount of a compound existing in water, usually expressed as parts per million.
Sanitizer: A chemical compound, such as chlorine and bromine, which disinfects (kills bacteria), kills algae, and oxidizes organic matter.
Shock: The process of introducing significant quantities of an oxidizer to water to bring about the chemical destruction of excess organic wastes.
Total Alkalinity (TA): The amount of bicarbonate, carbonate and hydroxides present in water. TA acts as a pH buffer.