Glossary
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Glossary of Pool Terms
There are 67 entries in this glossary.All
| Term | Definition |
|---|---|
| Flow Rate |
The volume of liquid (water) flowing past a given point in a specific time period, expressed in gallons per minute. |
| Free Available Chlorine |
Hypochlorous Acid, the chlorine in pool water that is not combined with ammonia or nitrogenous compounds, and therefore is available to kill bacteria entering the water. See also Available Chlorine. |
| Gelcoat |
The colored surface layer of a fiberglass pool or spa shell. This resin is applied to the mold during the manufacturing process, and is either of polyester or vinylester composition. |
| Gunite (shotcrete) |
A concrete and sand mixture sprayed into a reinforced steel form to create a pool shell. Plaster, paint, and some other form of cosmetic finish is applied on top of the Gunite structural shell. |
| Halogen |
A family of chemical elements containing Chlorine, Bromide, Fluorine, Iodine, and Astatine. With the exception of Astatine, the Halogen family is widely used for a variety of sanitizing situations. |
| Hydrogen Ion |
The positively charged nucleus of a hydrogen atom. Increasing levels of the Hydrogen Ion in the water will cause pH to be lowered. |
| Hydrotherapy Jets |
A spa fitting that blends air and water creating a high-velocity, turbulent stream of air-enriched water. |
| Hydrotherapy Spa |
A non-wooden vessel containing hot moving water for therapeutic use to ease stress, muscle strains and other physical problems. Popular construction types include thermoplastic shells and gunite/plaster interiors. |
| Hypochlorite |
An inorganic (unstabilized) family of chlorine compounds used in various forms to provide chlorine for water treatment. Includes Calcium Hypochlorite, Lithium Hypochlorite, and Sodium Hypochlorite. |
| Hypochlorous Acid |
The active sanitizing compound formed when any type of chlorine is put in water. |
| Impeller |
The “heart” of the centrifugal spa (and/or pool) pump. Rotating vanes create the suction flow of the water into the pump. |
| Influent |
The water entering a pump, filter, heater, or pipe. |
| Leaching |
The process of extracting a mineral from plaster interiors or tannic acid from wooden hot tubs. |
| Liquid Chlorine (Bleach) |
Sodium Hypochlorite solutions added to water as a disinfectant. Characteristics include very low levels of available chlorine (12-15%), high contribution to Total Dissolved Solids (3# of salt per gallon), and inconvenient to apply and handle. Should not be confused with Clorox that has even lower levels of available chlorine. |
| Make-Up Water |
Fresh water used to fill the spa. Also called Source Water. |
| Oxidation |
A chemical process for removing undesirable compounds from the water. |
| Ozone |
A gaseous molecule composed of three atoms of oxygen. It is created in ozone generators for oxidation. Its instability and short life in the water require that it be used only to supplement chlorine or bromine. |