Swimming Pool Glossary
EPA: Abbreviation for the U.S. Environmental Protection Agency.
EFFICACY: The power to produce an effect. Chlorine's efficacy is affected by many factors, including the sun, temperature, water balance and the water's chlorine demand.
ENZYMES: Used in commercial swimming pool formulations to break down and destroy oils in the swimming pool.
FIBREGLASS: Fine threads of glass which are available in the form of a rope or a mat. When polyester resins, catalysts and hardeners are applied to fibreglass, it can be formed or molded into pools, water tanks, boats and many other items.
FILL WATER: The water used in filling or topping up the swimming pool.
FILTER: A device that removes undissolved or suspended particles from water by the flow of the water through a porous substance (a filter medium or element). The three main types of filters used in pools are sand filters, cartridge filters and D.E. (diatomaceous earth) filters.
FILTER AID: A chemical compound added to the water, filter or skimmer that allows the existing filter to become more efficient. They are generally flocculants, coagulants and diatomaceous earth.
FILTER AREA: The toal surface area of the filter medium that is exposed to the flow of water from the pump, expressed in square metres.
FILTER CARTRIDGE: A disposable porous element made of paper or polyester and is used as the filter medium in cartridge-type filters.
FILTER CYCLE: The amount of time the filter has water flowing through it each day, expressed in hours.
FILTER ELEMENT: A device inside the filter which is designed to trap suspended solids as water flows through it from the pool.
FILTER MEDIUM: The material used in the filter to trap suspended dirt particles as the water flows through it. It is the polyester or paper in a cartridge filter element, the sand in a sand filter and the diatomaceous earth in a D.E. filter.
FILTER POWDER: A common name for diatomaceous earth (D.E.), the filter medium in a diatomaceous earth filter.
FILTER ROCK: Graded, rounded rock and/or gravel which is used to support the sand in sand filters.
FILTER SAND: Sand made up of hard and sharp silica or quartz (or similar), which have been graded for size and uniformity, and is used as the filter medium in sand filters. Nowadays it can also refer to clinoptilolite, the zeolite that is used as an alternative to quartz as the filter medium in sand filters.
FILTRATION RATE: The speed at which the water is travelling through the filter. It is expressed in litres per minute per square metre of filter area or in kilolitres per hour per square metre.
FLOC: See Flocculation.
FLOCCULANT: Also called a Flocculating Agent. Virtually the same as a coagulant, it is a chemical substance (such as alum) that is used to clump suspended particles or algae into a heavy mass, which can be caught by the filter or sinks to the bottom of the pool for vacuuming.
FLOCCULATION: The combination, clumping or coagulation of suspended particles so that they form small clumps or "lumps" (called floc).
FLOW RATE: The quantity of water flowing past a specific point in a specified time (e.g. the number of litres flowing through the filter in 1 hour).
FOAM: A froth of bubbles on the surface of the water. Usually comes from overuse of algaecide but may also be caused by soaps, oils or other contaminants carried into the water by swimmers. Enzymes may be used for foam control.
FREE AVAILABLE CHLORINE: The amount of free chlorine in the pool water that is available to oxidise, sanitise or disinfect the water. The level can be measured using a DPD1 test kit. It is also called residual chlorine or available chlorine.
GREEN HAIR: A condition caused by too much copper in the pool water or very high levels of chlorine.
GUNITE: A mixture of cement and sand which is sprayed onto the iron reinforced walls and floor of a hole to build a pool. The gunite surfaces are generally plastered.
GUTTER: Also called a Skimmer Gutter. An overflow channel at the edge of the pool through which floating debris, oil and other things flow and empty into the balance tank. Pools with gutters generally do not have skimmers.
HALOGENS: The chemical elements in Group VIIB of the Periodic Table of Elements: fluorine, chlorine, bromine and iodine. Only chlorine and bromine are used as oxidisers, disinfectants and sanitisers in swimming pools.
HAND SKIMMER: A net attached to a frame which is then attached to a pole and is used to remove large floating pollutants such as leaves and insects from the water's surface.
HARD WATER: Water that is high in calcium, magnesium or other salts, which makes it difficult for soap to lather. Hard water also has a tendency to form scale.
HARDNESS, calcium: The amount of calcium dissolved in the water. It is usually measured as calcium carbonate.
HARDNESS, total: The amount of calcium, magnesium and other salts dissolved in the water.
HERBICIDE: A chemical compound used to kill or control plant or algae growth.
HYDROCHLORIC ACID: Also called muriatic acid. A very strong acid used in pools to lower the pH or total alkalinity. It can also be used for cleaning an empty pool (acid washing).
HYDROGEN: The lightest chemical element. It is a component of water and a product of many chemical reactions. pH is a measure of positive Hydrogen ions in water.
HYDROGEN PEROXIDE: An unstable, colourless liquid which is used as an antiseptic in the home. It can used as an oxidising agent in pools. It is NOT compatible with the Pool Wizard.
HYPOBROMOUS ACID: The active form of bromine in water.
HYPOCHLORITE: The name given to a family of chlorine compounds including: calcium hypochlorite, sodium hypochlorite and lithium hypochlorite. They are used as oxidisers, disinfectants and sanitisers in pool water.
HYPOCHLOROUS ACID: The active form of chlorine in water.
IMPELLER: The rotating part of a pump that is responsible for the movement of water through the pump.
INLET: A fitting in the pool on the water return line. Water is pumped back into the pool through the inlet after filtration .
IONISER: A water sanitiser that uses electricity to generate metal ions, usually copper and silver. It works by passing a current through a set of electrodes. The copper is an algaecide and algaestat, while the silver is a bactericide. Ionisers can significantly reduce chlorine consumption. If the ion levels get too high, problems with staining or discolouration of the water occur.
IRON: Iron is a natural element that can cause the water to become clear brown or green in colour. It can also result in staining of the pool surfaces. Iron can be controlled by the addition of a suitable sequestering or chelating agent.
ISOCYANURATES: Also called stabilised chlorine. A group of chlorine pool sanitisers that contain stabiliser (cyanuric acid or isocyanuric acid) to protect the chlorine from the UV rays of the sun. The most common types are dichlor and trichlor. The granular form is dichlor, while the tablet or stick form is trichlor (usually used in a chlorine feeder). Stabilised chlorine should be used with care, to avoid problems such as chlorine lock that may be caused by overstabilisation.
L.S.I.: See Langelier Saturation Index
LANGELIER SATURATION INDEX: Also called Langelier Index or Saturation Index. This index can be used to determine water balance according to the levels of pH, Total Alkalinity, Calcium Hardness and water Temperature. When all the parameters are in balance, the water will neither be corrosive or scaling.
LEAF NET: Also called a Hand Skimmer. A net attached to a frame which is then attached to a pole and is used to remove large floating pollutants such as leaves and insects from the water's surface.
LINER: Also called a vinyl liner. The vinyl membrane that acts as the container to hold the water in one type of pool construction.
LIQUID ACID: Also called hydrochloric acid or muriatic acid. It is used for lowering pH, total alkalinity and for acid washing.
LIQUID CHLORINE: Chemically, sodium hypochlorite. It usually has 12% to 15% available chlorine and has a pH of 13. It is generally cheap, but difficult and dangerous to handle. It also loses its potency rapidly and is usually only used in large commercial pools.
LITHIUM HYPOCHLORITE: A dry granular chlorine compound with 35% available chlorine and has a pH of 10.7 . It dissolves quickly and can be used to superchlorinate vinyl-liner pools, painted pools and fiberglass pools.