A brief list of common spa terms designed to help the spa owner and the seasoned professional

Glossary of Terms

Bromamines: Compounds formed when bromine combines with nitrogen from body oils, urine, perspiration and the like. Unlike chloramines, bromamines have no pungent odor, and are effective sanitizers.

Bromine: A halogen sanitizer (in the same chemical family as chlorine) designed to kill bacteria and algae in the spa. Bromine is commonly used in stick, tablet or granular form.

Calcium Hardness (CH): The amount of dissolved calcium in the spa water. This should be approximately 150-220 parts per million (ppm). High levels of calcium can cause cloudy water and scaling. Low levels can cause harm to the spa equipment.

Chloramines: Chlorine and ammonia compounds which form in the water when chlorine reacts with organic contaminants in the water, such as body oils, urine, perspiration and the like. Chloramines can cause eye irritation as well as having a strong odor. Unlike bromamines, chloramines are weaker, slower sanitizers.

Chlorine: An efficient sanitizing chemical, designed to kill bacteria and algae in the spa.

Chlorine (or Bromine) Residual: The amount of chlorine or bromine remaining after chlorine or bromine demand has been satisfied. The residual is, therefore, the amount of sanitizer which is available to kill bacteria, viruses and algae.

Corrosion: The gradual wearing away of metal spa parts, usually caused by chemical action. Generally, corrosion is caused by low pH or by water with levels of TA, CH, pH or sanitizer which are outside the recommended ranges.

DPD: The preferred reagent used in test kits to measure the Free Available Chlorine.

Free Available Chlorine – The amount of chlorine available in the water to kill bacteria or algae. This is sometimes referred to as Free Chlorine or Available Chlorine.

Halogen: Any one of these five elements: fluorine, chlorine, bromine, iodine, and astatine.

MPS: Monopersulfate is the non-chlorine oxidizer used with the purification system.

Nitric Acid: A highly corrosive chemical that forms as a byproduct of the ozone generating process. Nitric acid is produced in very small quantities and is readily dissolved in the water stream with ozone.

Oxidizer: An oxidizing chemical used to prevent the buildup of contaminants, maximize sanitizer efficiency, minimize combined chlorine and improve water clarity.

Ozone: Ozone is a powerful oxidizing agent which is produced in nature and artificially by man. Ozone forms no byproducts of chloramines (ozone actually oxidizes chloramines) and will not alter the water’s pH.

Pathogen: A microorganism, such as bacterium, that causes disease.

pH: The measure of the spa water’s acidity and alkalinity. The recommended pH for the spa water is 7.4 to 7.6. Below 7.0 (considered neutral), the spa water is too acidic and can damage the heating system. Above 7.8, the water is too alkaline and can result in cloudy water, and scale formation on the shell and heater.

Reagent: A chemical material in liquid, powder or tablet form for use in chemical testing.

Sanitizer: Sanitizers are added and maintained at recommended residuals to protect bathers against pathogenic organisms which can cause disease and infection in spa water.

Scale: Rough, calcium-bearing deposits that can coat spa surfaces, heaters and plumbing lines and clog filters. Generally, scaling is caused by mineral content combined with high pH. Scale forms more readily at higher water temperatures.

Total Alkalinity (TA) – The measure in parts per million (ppm) of all the dissolved base/alkaline material in the water. Its function is to buffer large changes in pH.