ACID DEMAND: The amount of acid required to bring high pH or total alkalinity down to their proper levels. Determined by an acid demand test.

ACID RAIN: Precipitation having a low pH value caused by air polluted with sulfur dioxide, carbon dioxide or nitrous oxide.

ACID: A chemical substance containing hydrogen with the ability to neutralize alkaline materials. Acid is used to lower the pH or total alkalinity of swimming pool water. Most common are hydrochloric acid (muriatic) and dry acid (sodium bisulfate).

AIR BLEEDER ASSEMBLY: Located on the top of the filter, sometimes accompanied by a pressure gauge, the bleeder is opened to release air trapped in the filter.

AIR-RELIEF VALVE: A manually operated valve located on the top of a filter tank for relieving the pressure inside the filter or for removing the air trapped inside the filter (bleeding the filter). Sometimes called a Pressure-Relief Valve.

ALGAE: Microscopic plant-like organisms that contain chlorophyll. Algae are nourished by carbon dioxide (CO2) and use sunlight to carry out photosynthesis. They find their way into the pool by rain or wind and grow in colonies, resulting in algae blooms. Algae do not cause disease, but provide an ideal substrate for bacteria to thrive in. There are over 21,000 known species of algae. The most common pool types are black algae, blue-green algae, green algae and mustard algae. Pink algae or red algae-like organisms can be found, but are in fact bacteria. Maintaining proper sanitizer levels, shock treatments and super chlorination will help to prevent or destroy algae.

ALGAECIDE: Meaning to kill algae. Algaecides perform best as a backup to a routine sanitation program. They also help to kill airborne spores as they blow into the pool. A variety of algae treatment products are available including copper and silver compounds, quad compounds, chlorine enhancers and herbicides. Algaecides are often formulated for a specific type of algae (green algae, mustard algae, black algae) with black algae being the hardest to treat.

ALGAESTAT: An algaecide kills algae, while an algaestat retards and prevents its development and growth.

ALGICIDE: See Algaecide

ALKALI: Also called a Base. An alkali is the opposite of acid and is used to increase the pH or total alkalinity of swimming pool water. Most common are sodium carbonate or sodium hydroxide to increase pH, and sodium bicarbonate to increase total alkalinity.

ALKALINITY: Alkaline refers to the condition where the water's pH is above 7.0 (neutral) on the pH scale. It is the opposite of acidic. Alkalinity is the amount of carbonates and bicarbonates in the water, measured in ppm of Total Alkalinity.

ALUMINUM SULFATE: Also known as alum, this product is used as a flocculent which attracts suspended particles in the water together (green or cloudy pools). Alum sinks everything to the bottom, which is then vacuumed to waste. A small amount of alum can also be used as a sand filter additive.

AMMONIA: (NH3) it is a nitrogen-containing compound introduced into the water by swimmers as waste (perspiration or urine) or by other means. It quickly combines with chlorine to form bad-smelling chloramines, which are harmful to our health.

ANTI-FOAM: A chemical added to the water to reduce the foam. These products do not remove the source of the foaming. Shocking and superchlorination may help prevent foaming. Careful use of cheaper algaecides/ algaestats can prevent foaming.

Automatic covers: Solid, reinforced vinyl which rolls onto a reel on one end of the pool and attaches on the sides into small aluminum tracks. Can be motorized or hand crank. Some models may snap the sides into small anchors placed into the deck, providing more shape flexibility. Provides safety (with water pumped off), debris protection and heat/chemical/water retention.

AUTOMATIC POOL CLEANER: A pool maintenance system that will brush or vacuum dirt and debris from the interior of the pool automatically. Some cleaners work on low-voltage electricity, others on the pump's suction line. The pool cleaner may be programmable, automatic or may move randomly around the pool. Some cleaners can climb the walls of the pool, while others only clean the floor.

AVAILABLE CHLORINE CONTENT: A term used to compare the amount of oxidising power that chorine-containing products have when compared to gas chlorine(Cl2). It permits easy comparison of relative values of chlorine compounds.

AVAILABLE CHLORINE: The amount of free chlorine that is available to sanitize or disinfect the water. It is also called Residual Chlorine and Free Available Chlorine.

BACKFILL: The repositioning of the soil after construction of a pool.

BACKFLOW: The back-pressure of water in a pipe in the opposite direction to normal flow.

BACKWASH: The process of thoroughly cleaning the filter medium and/or elements by reversing the flow of water through the filter to waste.

BACTERIA: Unicellular microorganisms of various forms. Some are pathogens, which can cause infectious diseases. Bacteria are controlled by chlorine, bromine or other sanitizers or disinfectants.

BACTERICIDE: Kills bacteria. Chlorine is a bactericide and germicide. Silver "algaecides" are actually more bactericide, and are useful on pink "algae".

BAKING SODA: Chemically, Sodium Bicarbonate. It is white powder used to raise the total alkalinity of pool water without having much effect on pH. It will only increase pH up to 8.5, regardless of the quantity used. Care should be taken, however, to avoid adding large quantities at one time.

BALANCED WATER: Balanced water is the result when all of your chemical parameters are where they should be, and thus "balance" each other. The key components of water balance are pH, Total Alkalinity, Calcium Hardness and Temperature, as measured using the Langelier Index of water balance.

BALANCED WATER: Balanced water is the result when all of your chemical parameters are within the tolerance limits. The most important parameters of water balance are pH, Total Alkalinity, Calcium Hardness and Temperature, as measured using the Langelier Saturation Index.

BALL VALVE: A device with a hollowed out ball inside which can be turned with an external handle to decrease or increase flow.

BASE DEMAND: A titration test used to determine proper amounts of base (pH increaser) to reach correct levels. For example, to raise pH from 7.2 7.6, your water may "demand" 2 cups of soda ash.

BASE DEMAND: A titration test used to determine the amount of a base (alkali) required to increase the pH to the correct level.

BASE: Chemicals of alkaline nature which will counteract the pH of an acid. Common bases used around the pool include Soda Ash, Sodium Bicarbonate and Sodium Carbonate. A base is the opposite of an acid. See Alkali

BASE: Those chemicals of alkaline nature which will counteract the pH of an acid, eventually neutralizing at 7.0. Common bases used around the pool would include Soda Ash, Sodium Bicarbonate, Sodium Carbonate and Sodium Sesquicarbonate.

BCDMH: Chemically, "bromochlorodimethylhydantoin", it is a bromine sanitizer. When BCDMH dissolves in water it produces Hypobromous Acid and Hypochlorous Acid.

BICARB: See Sodium Bicarbonate...

BIGUANIDES: The name for a certain class of sanitizers using the polymer PHMB, the only nonhalogen sanitizer available for pool and spa use. Soft Swim and Baquacil are manufacturers of this technology.

BLEACH: This term usually refers to liquid chlorine. It is the same chemical used in the home, but pool chlorine (sodium hypochlorite) has 12% - 15% available chlorine while laundry bleach only has about 5% available chlorine.

BLEACHING OUT: At above 10ppm free available chlorine in a pool, a DPD test kit often indicates zero chlorine because the reagent is being destroyed. If you observe an initial pink color which then rapidly fades, you probably have far too much residual chlorine in the water.

BLOWER: Plumbed into the spa return line, air is injected to produce fun bubbles and a hydrotherapy effect in the spa.

BLUE FINGERNAILS: A condition caused by too much free copper in the pool water. Can result from cheaper copper-based algaecides, overuse of these algaecides or corrosive water. See also Green Hair.

BOOSTER PUMP: In addition to the filter pump, a booster pump may be necessary to power some automatic pool cleaners.

BREAKPOINT CHLORINATION: When you shock treat your pool, the goal is to reach a high enough level of free chlorine to break apart all molecular bonds; specifically the combined chlorine molecules, ammonia or nitrogen compounds and to completely oxidize all organic matter. Adding enough chlorine to achieve this is breakpoint chlorination. Chlorine added after that point will be free available chlorine.

BROMAMINES: A combined bromine ammonia molecule. Unlike chloramines, which are strong smelling and offer no sanitizing properties, bromamine compounds continue to sanitize.

BROMIDE: A common term for a bromide salt which, when added to water becomes hypobromous acid, the active form of bromine. It is used as a disinfectant in swimming pools.

BROMINATOR: A mechanical or electrical device for dispensing bromine at a controlled rate. It is most commonly a canister or floater filled with bromine tablets.

BROMINE: A member of the halogen family commonly used as a sanitizer or disinfectant to destroy bacteria and algae in swimming pools. It is resistant to heat and rapid pH fluctuations. Available as a tablet or as sodium bromide, a granular salt.

BTU: British Thermal Unit. A unit of measurement for the use of gas by a gas appliance. Pool heaters are rated by their consumption.

BUFFER: A base such as Sodium Bicarbonate (Baking Soda), added to your pool will increase alkalinity which increases the buffering capacity of the pool; or, your pool's resistance to pH change.

BUFFERING CAPACITY: The ability of the pool to resist changes in pH, which prevents water balance. The buffering capacity is given by the alkalinity, a close cousin to pH. If your pH bounces, or resumes previous levels soon after adjustment, your buffering capacity is too low. Check your total alkalinity.

BYPASS: An arrangement of pipes, gates and valves by which the flow of water may be passed around the filter rather than through it, and usually refers to circulating the water without filtration.

CALCIUM CARBONATE: Known as scale, crystalline deposits of calcium may form on your pool surfaces, equipment, or even line your pipes like cholesterol in your arteries. Properly balanced water can prevent this.

CALCIUM CHLORIDE: The flaked calcium salt used to raise levels of Calcium Hardness in your pool water. Also good for snow melting.

CALCIUM HARDNESS: A titration test is used to determine levels of the mineral calcium dissolved in the pool water.

CALCIUM HYPOCHLORITE: A compound of chlorine and calcium used as a disinfectant, sanitizer, bactericide, algaecide and oxidizer in swimming pool water. It is available as a white granular powder which usually contains 65% - 70% available chlorine and has a pH of 11.8 . It is also used as a disinfectant in drinking water.

CAPACITY: The gallonage of the pool. Want the formula?

CARBON DIOXIDE: A gas, which when present in the water, provides necessary food for the growth of algae.

CARBONATE: Primary in the make up of total alkalinity and TDS.

Cartridge filter elements and DE filter grids are two examples.

CARTRIDGE FILTER: A water filter that uses a replaceable porous element made of paper or polyester.

CARTRIDGE: A disposable porous element made of paper or polyester which is used as the filter medium in cartridge filters.

CHECK VALVE: A mechanical device in a pipe that permits the flow of water in one direction only. Also called a one-way valve or a non-return valve.

CHELATED COPPER: Copper algaecides that contain a special ingredient to prevent the copper from staining the pool surfaces or producing colored water.

CHELATOR: A chelating agent is a water soluble molecule that can bond tightly with metal ions, keeping them from coming out of suspension and depositing their stains and scale onto pool surfaces and equipment. Similar to sequestering agents, chelators are found in such products as Resist and SeaKlear.

CHEMICAL FEEDER: A device that dispenses chemicals into the pool water at a predetermined rate. Some provide chlorine or bromine while others add pH-adjusting chemicals.

CHITIN: A naturally occurring polymer found in the shells of crabs and lobsters. Contained in the product SeaKlear, chitin acts as a coagulant and flocculent for oils, metals and organic materials.

CHLORAMINES: The chlorine molecule is strongly attracted to nitrogen and ammonia. When these two hook up, they form a chloramine, which are undesirable, foul smelling, space taking, compounds that require shocking the pool water to get rid of.

CHLORINATOR: A mechanical or electrical device for adding chlorine to a pool at a controlled rate. Most often a floater filled with tablets of chlorine or an in-line feeder.

CHLORINE DEMAND: The quantity of free available chlorine removed during the process of sanitizing. The amount of organic and non organic material contained in the water will "demand" a certain level of oxidizer to be destroyed.

CHLORINE ENHANCER: A chemical compound used in conjunction with chlorine, that makes the chlorine perform better as an algaecide.

CHLORINE GENERATOR: An electrical device that generates chlorine from a salt solution. The salt solution may be in a separate tank or may be in the pool itself.

CHLORINE LOCK: If the level of cyanuric acid (stabilizer) in the water is much over 80ppm, the chlorine becomes trapped and is unable to oxidize effectively. Despite being able to measure normal chlorine levels, the Redox potential is very low, indicating a lack of oxidizer. The only way to fix this is to drain some of the water and refill the pool. Care should be taken when using stabilized chlorine products (dichlor or trichlor) to avoid the level of cyanuric acid increasing too much.

CHLORINE NEUTRALISER: A chemical used to deactivate or destroy chlorine. It is used in better test kits to prevent the bleaching effect of the chlorine and consequently to increase the accuracy of the tests.

CHLORINE RESIDUAL: Also called Free Available Chlorine. The amount of chlorine left in the pool water after the chlorine demand has been satisfied.

CHLORINE, combined: That portion of total available chlorine left over when free available is subtracted. The measure of chlorine which has already attached itself to other molecules or organisms. Most of this is made up of chloramines.

CHLORINE, free available: Free, available chlorine is that which is active, not combined with ammonia or a nitrogen molecule, and ready to react to destroy organic material.

CHLORINE, total available: The sum of combined and free chlorine levels. With a DPD test kit, one determines free available level, then total available. The difference, if any, is the level of combined chlorine.

CHLORINE, total: The sum of combined and free available chlorine levels. With a DPD test kit, DPD1 determines free available chlorine and DPD3 shows total chlorine. The difference, if any, is the level of combined chlorine.

CHLORINE: A member of the halogen family of sanitizers. Its use in swimming pools is in the form of a gas, as a liquid, in granular or tablet forms. When added to water it acts as an oxidizer, sanitizer, disinfectant and biocidal agent.

CIRCUIT BREAKER: A switch which allows manual override of an electrical circuit. It also automatically breaks the circuit when current fluctuations are detected.

CIRCULATION SYSTEM: The "circuit" of plumbing which continuously carries the water out of the pool, through the pump & filter, and returns it to the pool.

CLARIFIER: A clarifier is a chemical used as a coagulant of suspended micro particles. Helps the filter by clumping smaller particles into filterable sizes.

CLARITY: The degree or measure of the transparency of water.

CLINOPTILOLITE: The zeolite that is used as an alternative to quartz as the filter medium in sand filters.

COAGULANT: The properties of a chemical used in the assemblage and precipitation of suspended material which may make the pool appear cloudy.

COMBINED CHLORINE: See Chlorine, combined.

COMPENSATION TANK: The tank into which the water from the gutters or skimmer gutters flows. The tank serves to ensure that the pool has enough water to overflow regardless of the number of swimmers and independent of evaporation and splash-out losses.

CONDITIONER: Chemically known as cyanuric acid and also called stabilizer. It protects chlorine in the water against the effects of the sun's UV rays.

CONDUIT: A pipe, usually gray PVC or flexible PVC designed to carry wires from a source (i.e. time clock) to a load (i.e. pump motor).

CONTAMINANTS: The general name for any micro particle or organism which reduces water clarity, quality or presents health hazards. Filtering, oxidising and sanitizing are necessary to destroy the contaminants.

COPING: The capstone on top of the bond beam which finishes the edge around a pool or spa. It may be precast concrete or brick. On vinyl liner pools pre fab coping is usually part of an integrated system for the wall, vinyl liner and deck.

COPPER ALGAECIDE: A chemical compound that contains the element copper. Most copper algaecides contain ingredients that prevent the copper from staining but do not affect copper's ability to kill algae. These are known as chelated copper algaecides.

COPPER SULFATE: Similar to aluminum sulfate, this chemical provides a coagulating and flocculent function in water. Used in ponds. This amount of copper would stain swimming pools.

COPPER: An effective algaestat and algaecide and is one of nature's natural elements. It may also be used in the equipment and plumbing in swimming pools. High levels of copper may stain hair, fingernails or pool surfaces and can also result in green, brown or blue water.

CORROSION: The effects of an acidic pool environment, one in which the pH and/or alkalinity are very low. Corrosion in the form of etching, pitting or erosion of pool equipment and surfaces is the result.

COUPLING: A plumbing fitting designed to join two pieces of pipe.

COVER, hard-top: A cover used on pools that rests on the edge of the pool deck and does not come into contact with the water.

COVER, solar: A floating cover that increases the water temperature by absorption and transmission of solar radiation and reduces evaporation and pollution from the environment.

COVER, winter: A cover that is secured around the edges of a pool when the pool is closed for the season.

CYANURIC ACID: Also called conditioner and stabilizer. A granular chemical added to the pool water which provides a shield to chlorine for protection from the sun's UV radiation. It is also found in dichlor/ trichlor products.

D.E. FILTER: See Diatomaceous Earth Filter

DEFOAMER: Also called anti-foam. A chemical added to the water to destroy the foam. These products do not remove the source of the foaming. Shocking and superchlorination may help prevent foaming. Controlled use of certain of the cheaper algaecides can prevent their resulting in foaming.

DIATOMACEOUS EARTH FILTER: A filter designed to use diatomaceous earth (D.E.) as the filter medium. The D.E. is added through the skimmer with the pump on, which deposits the D.E. on a grid. The D.E. becomes the filter medium.

DIATOMACEOUS EARTH: Also called D.E. A white powder composed of fossilized skeletons of unicellular organisms called diatoms. The skeletons are porous and have microscopic spaces. The powder is added through the skimmer with the pump on and deposits itself on a grid. The powder then becomes the filter medium.

DICHLOR: The common name for Sodium Dichlor Isocyanuric Acid. A quick dissolving chlorine compound made up of chlorine and cyanuric acid (stabilizer) and has a pH of 6.9. Shock treatment with dichlor is not recommended as it may result in overstabilisation and chlorine lock. If dichlor is used, a monthly check of the cyanuric acid level is recommended, to prevent overstabilisation and chlorine lock.

DIRECTIONS: What you should read before using any chemicals.

DIRT DEMAND: The demand that your pool has for dirt. This level is invertedly proportional to available time for cleaning. If you remove the dirt from the pool, you have created a dirt deficit, and the pool will actually suck dirt out of the air to maintain its dirt demand.

DISINFECT: To kill all pathogenic (disease-causing) organisms.

DISINFECTANT: Chemicals or processes which work to destroy vegetative forms of microorganisms and other contaminants. Examples are chlorine, bromine, SoftSwim, ionizers and copper and silver algaecides.

DISSOLVED SOLIDS: See Total Dissolved Solids

DIVERTER VALVE: Used in a twin port skimmer, a diverter allows the operator to manipulate the amount of flow from the main drain and skimmer to the pump.

DPD: A method of testing for chlorine levels in the pool water. Unlike OTO, DPD testing allows determination of total and free available chlorine levels, which, through subtraction, give us, combined levels.

DRAIN: A plumbing fitting installed on the suction side of the pump in pools. Also called the main drain, it is located in the deepest part of the pool. Main drains are connected to the pump for circulation, filtration and emptying of the pool.

DRY ACID: Sodium bisulfate, a granular form of acid, used to lower pH and alkalinity in the water. Safer and less caustic than muriatic acid. Usually available as a "pH decreaser."

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.

EFFLUENT: The water that flows out of the pump, on its way through the filter, heating and treating equipment, and returning to the pool. Also known as the pressure side.

ELBOW: A 90 or 45 degree plumbing fitting. Used where your pipes take a turn.

ENZYMES: Used in commercial swimming pool formulations to break down and destroy oils in the swimming pool.

EPA: Abbreviation for the U.S. Environmental Protection Agency.

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 fiberglass, it can be formed or molded into pools, water tanks, boats and many other items.

FILL WATER: Used in filling or adding to the water level. Whether from the hose or from a well, your fill water brings its own chemical make up and water balance (or lack thereof).

FILMX: A compound of citric acid used in cleaning plaster and other pool areas. Safe replacement for muriatic acid.

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 total surface area of the filter medium that is exposed to the flow of water from the pump, expressed in square meters.

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: A finely graded material, such as sand, diatomaceous earth, polyester fabric or anthracite coal that removes suspended particles from water passing through it.

FILTER POWDER: A common name for diatomaceous earth (D.E.), the filter medium in a diatomaceous earth filter.

FILTER PUMP: The device that pulls water from the pool and pushes it through the filter on its way back to the pool.

FILTER ROCK: Graded, rounded rock and/or gravel which are 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.

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.

FILTRATION RATE: The speed at which the water is traveling through the filter. It is expressed in liters per minute per square meter of filter area or in kilolitres per hour per square meter.

FLOC: See Flocculation.

FLOCCULANT: Essentially the same as a coagulant, this chemical (such as alum) is used to combined suspended alkaline material and/or algae into a heavy gel, which sinks to the bottom for vacuuming.

FLOCCULATION: The combination, clumping or coagulation of suspended particles so that they form small clumps or "lumps" (called flock).

FLOW RATE: The quantity of water flowing past a specific point in a specified time (e.g. the number of liters 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.

FOAMING: A term used to describe surface foam on your water, esp. in spas/hot tubs. Foaming is caused by high TDS levels working in combination with soft water and oils. Certain low grade algaecides can foam when added to pool or spa. Use enzymes for foam control.

FREE AVAILABLE CHLORINE: The amount of free chlorine in the pool water that is available to oxidize, sanitize or disinfect the water. The level can be measured using a

GAS VALVE: An electronic valve in the pool heater that directs gas flow from the meter to the pilot and the burner tray.

GATE VALVE: The type that spins "leftyloosey; rightytighty".

GREEN HAIR: A condition caused by too much copper in the pool water.

GROUND FAULT CIRCUIT INTERRUPTER: A GFCI device protects a circuit from branching off by deenergizing the path of electricity very quickly when it senses current loss. An important safety device around water (the pool?).

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 oxidizers, disinfectants and sanitizers 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 COVER: A cover which rests on the edge or coping of the spa or small pool. Provides a barrier to debris and possibly people, while keeping the heat trapped in.

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.

HEAT EXCHANGER: A set of 8 or 10 ribbed copper tubes that absorb the heat produced below it and transfer it to the water cycling through its tubes.

HEAT PUMP: The antithesis of the air conditioner, the heat pump's cooling coil removes heat from the air while the condenser coil transfers it to water cycling through it.

HEATER: A device used to heat the water. It may be electric, fuel operated or solar powered heat.

HERBICIDE: A chemical compound used to kill or control plant or algae growth.

HOT TUB: Usually considered a circular, wooden vessel filled with heated and circulated water.

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 PEROXIDE: An unstable, colorless liquid which is used as an antiseptic in the home. It can be used as an oxidising agent in pools. It is NOT compatible with the Pool Wizard.

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.

HYDROSTATIC PRESSURE: A force involving built up ground water which creates upward pressure beneath the pool shell.

HYDROSTATIC RELIEF VALVE: Fitting(s) installed in the floor of the pool designed to manually or automatically release hydrostatic pressure beneath the pool by allowing ground water into the pool.

HYPOBROMOUS ACID: The active form of bromine in water.

HYPOCHLORITE: A family of chlorine compounds such as Calcium Hypochlorite and Lithium Hypochlorite, both granular, and the liquid Sodium Hypochlorite. When these compounds contact water, they release Hypochlorous Acid, the active sanitizing agent.

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.

INFLUENT: The water coming into and up to the impeller from the suction lines. These pipes are under vacuum pressure.

INLET: A fitting in the pool on the water return line. Water is pumped back into the pool through the inlet after filtration.

IONIZER: An ionizer is a device mounted on your return line, and through which water flowing will receive charged metal ions. Manufacturers may use a copper anode and/or silver. Copper is an algaecide and algaestat, while silver is known for its properties as a bactericide. This electric, limited technology has been replaced by the Vision System.

IRON: Usually introduced into the water from iron plumbing or from well water, Ferric Iron can stain surfaces, while Ferrous Iron will turn your water a clear green color.

ISOCYANURATES: Also called stabilized chlorine. A group of chlorine pool sanitizers that contain stabilizer (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). Stabilized chlorine should be used with care, to avoid problems such as chlorine lock that may be caused by overstabilisation.

JANDY VALVE: A brand name of a three way valve, which has simplified pool plumbing.

JET PUMP: Used in spas to provide additional thrust into the hydrotherapy jets.

L.S.I.: See Langelier Saturation Index

LADDER BUMPERS: Rubber caps or inserts which protect the pool plaster or vinyl liner from the sharp steel ends of the ladder.

LANGELIER INDEX: Also called the Saturation Index, Mr. Langelier devised a system to determine water balance by assigning values to levels of pH, Total Alkalinity, Calcium Hardness and water Temperature. When all parameters are in balance, the water will neither be corrosive or scaling.

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.

LATERALS: Elongated, capped plastic nipples at the bottom of a sand filter which are slotted to allow for water passage while keeping the sand in the filter tank.

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.

LOAD: An electric device which consumes energy, placing a load on the source.

LOW WATER SUCTION: An influent fitting, typically low on the wall in the deep end of a vinyl liner pool. A cheaper alternative to a main drain.

MAGNESIUM HARDNESS: A measure of the amount of magnesium dissolved in the water. It is part of total hardness.

MAIN DRAIN: This usually refers to the drain that is located in the deepest part of the pool.

MAKE-UP WATER: Also called top up or refill water. It is the water used to replace water lost to evaporation, splash-out, leaks and backwashing.

MARBELITE: Also referred to as Plaster. It is a mixture of white cement and white marble dust used as an interior finish over the gunite or shotcrete of a pool. It can be given a color or it may be left white.

MARCITE: See Marbelite

MECHANICAL SEAL: A seal behind the impeller which prevents water from running out along the shaft of a motor. aka; pump seal.

Mesh Covers: These stretch tightly across the pool like a trampoline. The only covers which can be called safety covers in that the mesh polypropylene allows precipitation to pass through.

MICRON: A unit of length equal to 1 millionth of a meter. Microns are used to describe the pore size of filter media. Sand filters have openings of 25 to 30 microns; cartridge filters have openings of 8 to 16 microns; and D.E. (diatomaceous earth) filters have openings of 1 to 5 microns. Zeolite used in sand filters have openings of 3 to 6 microns. A grain of salt is between 90 and 110 microns.

MICROORGANISM: A living, breathing creature in your pool. The purpose of disinfectants is to remove such "infectants".

MINERAL: Substances such as Calcium, Manganese, Magnesium, Nickel, Copper, Silver, Zinc, Iron, Cobalt or Aluminum. Their presence in high non-chelated concentrations can lead to stains or scale formation. The measure of water hardness is dependent on these minerals.

MINERALS: Such as Calcium, Manganese, Magnesium, Nickel, Copper, Silver, Iron, Cobalt or Aluminum. Their presence in high nonchelated concentrations can lead to stains & scale when conditions are right.

MOTOR: A machine for converting electrical energy into mechanical energy. Your motor is known as the dry end of the filter pump. It drives the impeller, which moves the water.

MULTIPORT VALVE: Also called a 6-way or 6-port valve. Water from the pump can be diverted for various functions by turning the valve handle. The water may: 1. be sent to waste, 2. be used for backwashing, 3. bypass the filter for maximum circulation, 4. filter normally, 5. be used to rinse the filter, or 6. the valve may have all its ports closed. The pump must be off before changing a valve setting.

MURIATIC ACID: Also called liquid acid or hydrochloric acid. A very strong acid used in pools to lower the pH and total alkalinity. It can also be used for cleaning an empty pool (acid washing).

NASCENT OXYGEN: A single oxygen atom, not yet bonded to anything. Extremely powerful oxidizer when harnessed.

NEUTRALISER: A chemical used to deactivate or destroy chlorine or bromine. It is used in better test kits in order to increase the accuracy of the pool water tests.

NITROGEN: A gas that causes algae to bloom and disables chlorine. It is introduced into the water by rain and by swimmers. Maintaining proper chlorine levels will prevent nitrogen from becoming a problem. Superchlorination can destroy nitrogen and nitrogenous compounds.

NON-CHLORINE SHOCK: A granular form of potassium peroxymonosulfate (potassium monopersulfate, potassium permonosulfate), used to oxidize materials such as microorganisms, contaminants (ammonia, nitrogen, swimmer waste,) or chloramines.

ORGANIC WASTE: Also called swimmer or bather waste. Refers to the soap, deodorant, suntan lotion, body oils, sweat, and spit, urine . . . that is introduced into the water by swimmers, as well as the leaves, dust and insects that end up in the pool. The organic waste may form undesirable chloramines, which require large amounts of chlorine or non-chlorine shock to be destroyed.

ORGANIC: Refers to chemical compounds containing carbon atoms bonded together with other elements. The main groups of organic substances found in water are proteins, carbohydrates, fats and oils.

ORP: The abbreviation for Oxidation-Reduction Potential. It is a measurement of the oxidizer’s (e.g. chlorine) ability to oxidize contaminants versus the contaminants' (e.g. algae) ability to reduce the oxidizer. It is an indication of the level of free available oxidizer in the water. ORP is generally used with automated dosage systems and can give a fair idea of the sanitation of the water. It is not a measure of the total or available chlorine. Sometimes called Redox Potential.

OTO: The abbreviation for Ortho Tolidine. A chemical reagent used to test the total chlorine level in water at normal temperatures. It can measure free available chlorine if the water is first cooled to 1°C. Its results depend on pH, time and concentration of chlorine. Due to its toxicity, the use of OTO is restricted or prohibited in many western countries.

OXIDATION: The "burning up" of organic waste and compounds in the pool water. It also refers to what you may see on your metal pool surfaces if your water is corrosive. Rust is a form of this kind of oxidation.

OXIDIZER: Any compound that removes or destroys organic waste and organic compounds in the water.

OZONATOR: An electrical device that produces ozone that is introduced into the water as a sanitizer.

OZONE: The molecule containing three atoms of oxygen; known to be a very powerful sanitizer. Ozone producing equipment creates this molecule by UV radiation or corona discharge generators.

PATHOGEN: Also called a pathogenic organism. An organism that can cause illness, disease or death.

pH: The scale of relative acidity or alkalinity, expressed in logarithmic numbers from 0 14, with 7.0 being neutral. What's really being measured is the hydrogen ion concentration. Some would say pH stands for Power of Hydrogen.

PHENOL RED: A chemical reagent dye used to test pH. It can measure pH from 6.8 to 8.4. The tablet form usually incorporates a chlorine neutralizer for more accurate results.

PHOTOMETER: An electrical instrument for testing pool water conditions, which measures the colors electronically rather than visually, giving more accurate results.

PLASTER: A common type of interior finish applied over the concrete shell of an in ground swimming pool.

PLUNGER: The sliding disc assembly that changes valve position in a push pull valve. For example; up for backwash, down for filtration.

POLYMER: A large substance comprising of small repeating molecules. Many coagulants are made from organic polymers as are algaecides and algaestats.

POTASSIUM PERMONOSULFATE: See nonchlorine shock.

POTASSIUM PEROXYMONOSULFATE: See Non-chlorine Shock.

PPM: Parts per million. A method of assigning value to certain concentrations of chemicals in the water. For example, alkalinity should be kept at 80120 parts per million, by weight and in relation to the water it's dissolved in.

PRECIPITATION: To precipitate is to come out of solution; become insoluble by result of chemical action. Material forced out of solution, purposefully or accidentally, will then settle, stain or scale, or remain suspended in the water.

PRESSURE CHECK: A test for the rate of water flow; also a test for leaks in plumbing by placing a line in question under pressure and waiting for the pressure to drop.

PRESSURE GAUGE: A device indicating pressure in a filter system. Provides a determination of how the system is operating, and informs us when service is required.

PRESSURE GAUGE: A gauge with a dial indicating the pressure in a closed container such as a sand filter.

PRESSURE SIDE: The return side of the plumbing. The section from the pump impeller towards the pool.

PRESSURE SWITCH: A switch used in pool heaters which opens when the flow rate is insufficient for safe heater operation. This disrupts the circuit in the heater, preventing it from firing.

PUMP CAPACITY: The volume of water a pump is capable of moving during a specified period of time. This is usually given in liters per minute or kilolitres per hour (m3/h).

PUMP CURVE: Also called a Pump Performance Curve. It is a graph that shows a pump's water flow capacity at any given resistance.

PUMP STRAINER BASKET: A device placed on the suction side of the pump, which contains a removable strainer basket designed to trap large debris in the water flow without causing restriction. Sometimes called a Pump Leaf Trap.

PUMP: A mechanical device which causes water to flow under pressure for the purpose of filtration or circulation.

PUSHPULL VALVE: A two position valve used for backwashing sand or DE filters.

PVC: Polyvinyl chloride, which is used to make flexible and rigid PVC pipe used for pool plumbing.

QUATERNARY AMMONIUM COMPOUND: A type of algaecide composed of ammonia compounds. Effective algaestat for green and blue/green algae.

RATE OF FLOW: Quantity of water flowing past a designated point within a specified time period, measured in gallons per minute (gpm).

REAGENT: The chemical indicators used in testing various aspects of water quality.

REBAR: Reinforcement bar, used to add strength to a concrete. After excavation of an in ground pool, a steel cage is formed out of rebar, and the gunite shell is shot over and surrounding it.

Recirculate: This setting bypasses the filter, water coming into the multiport does a Uturn and heads back towards the pool. Used only when the filter is broken (at least it's circulating), or when adding specialty chemicals which specify using this setting.

REDOX POTENTIAL: The abbreviation for Reduction-Oxidation Potential. It is a measurement of the oxidizer’s (e.g. chlorine) ability to oxidize contaminants versus the contaminants' (e.g. algae) ability to reduce the oxidizer. It is an indication of the level of free available oxidizer in the water. ORP is generally used with automated dosage systems and can give a fair idea of the sanitation of the water. It is not a measure of the total or available chlorine. Sometimes called ORP.

RESIDUAL BROMINE: The amount of free available bromine remaining in the water after the bromine demand has been satisfied.

RESIDUAL CHLORINE: The amount of free available chlorine remaining in the water after the chlorine demand has been satisfied.

RESIDUAL: Usually refers to free available chlorine levels remaining in the pool after initial treatment or activity with contaminants.

RESTRICTED FLOW: The term used to describe a condition preventing full flow of water. Restriction can occur with full skimmer or strainer baskets, obstructions in the plumbing, dirty filter, undersized plumbing or equipment, or placing devices like, heaters, cleaners or fountains in the circulation system. Restriction on the suction side creates higher vacuum, (or suction) while on the pressure side creates higher pressure.

Rinse: After backwashing, it's a good idea to rinse for 1520 seconds to remove any residual dirt that may "poof!" back into your pool after backwashing. Rinse flows through the water in filter fashion, say, top to bottom, but effluent is sent out the waste line.

SAND FILTER: A filter tank, usually fiberglass or ABS plastic, filled with sand and gravel. The pump diffuses water over the top of the sand bed, and forces it through the sand and into the laterals on the bottom.

SAND: The filter medium used by a sand filter. It usually refers to quartz or silica, but may also refer to zeolites.

SANITIZER: A chemical agent used to remove unwanted contaminants.

SCALE: The precipitate that forms on surfaces in contact with water when the calcium hardness, pH or total alkalinity levels are too high. Scale may appear as grey, white or dark streaks on the plaster, fiberglass or vinyl. It may also appear as a hard crust at the waterline.

SCUM: The foreign matter which floats to the surface of the water and forms a layer or a film. It can also refer to a residue deposited on the tiles or walls of the pool.

SEDIMENT: The solid material that precipitates out of the water and settles to the floor of the pool.

SEQUESTERING AGENT: Also called Chelating Agent. A chemical or compound that combines with dissolved metals or minerals in the water to prevent them from coming out of solution, thus coloring the water or causing stains.

SEQUESTRANT: A chemical which holds metals in solution and helps prevent scaling. See Sequestering Agent.

SHOCK TREAT: Adding large amounts of an oxidizer such as chlorine, hydrogen peroxide or potassium peroxymonosulfate to the water to destroy ammonia and nitrogen compounds, chloramines and other contaminants.

SHOCK: As a noun it loosely describes the products used in shocking, such as hypochlorites, potassium permonysulfate or hydrogen peroxide. As a verb it describes the act of bringing the sanitizer level up so high that breakpoint chlorination is reached. When breakpoint is reached, a "shock" or perhaps a "lightning bolt" is a better analogy, is sent through the water, tearing apart molecules and slashing through cell walls. Ultimate purification, man.

SHOTCRETE: A different type of application of the concrete and sand mix which is used to "shoot the shell". Gunite is pumped dry and mixed with water at the gun, whereas shotcrete is pumped wet.

SKIMMER BASKET: A removable basket or strainer placed in the skimmer, which is designed to trap large solids from the water before they get to the pump or filter.

SKIMMER GUTTER: Also called a Gutter. An overflow channel at the edge of the pool through which floating debris, oil and other things flow and empty into the compensation tank. Pools with gutters generally do not have skimmers.

SKIMMER NET: Attached to a telescopic pole, a leaf rake is a very useful tool in keeping the pool clean. Also called a skimmer net are the flat, "dip and flip" nets, which aren't so useful.

SKIMMER WEIR: The small floating door on the side of the skimmer over which water flows on its way to the skimmer. The weir prevents debris from floating back into the pool when the pump is off.

SKIMMER: A surface skimmer is a plumbing fitting set at water level, containing a weir mechanism and a debris basket. The skimmer is part of the suction side circulation system.

SLURRY: Water containing a high concentration of suspended solids. D.E. is usually added to the filter as a slurry by mixing the D.E. in some water.

SODA ASH: Chemically, Sodium Carbonate. A base that is used to raise the pH of acidic (below pH 7.0) water.

SODIUM BICARBONATE: Also called Baking Soda or Bicarb. A base that is used to raise Total Alkalinity in pool water with only a slight effect on the pH. Sodium bicarbonate can only raise the pH of the water to 8.5, regardless of the amount used. Care should be taken, however, to avoid adding large quantities at one time.

SODIUM BISULFATE: Also called Dry Acid. A granular form of acid used to lower the pH or Total Alkalinity of pool water.

SODIUM BROMIDE: A salt of bromine which is used to raise the bromine levels in a pool before using bromine tablets.

SODIUM CARBONATE: Also called Soda Ash. A base that is used to raise the pH of acidic (below pH 7.0) water.

SODIUM DICHLOR: A granular, stabilized organic chlorine compound providing 56% or 62% available chlorine that has a pH of 6.9. Used for regular chlorination. Should be used with caution for superchlorination as it can cause the stabilizer level to rise too high, resulting in chlorine lock.

SODIUM HYPOCHLORITE: Liquid chlorine for use in pools. It usually provides 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.

SODIUM MONOPERSULFATE: Active ingredient and chemical name of a non-chlorine shock treatment or non-chlorine oxidizer. See Non-Chlorine Shock.

SODIUM PERSULFATE: Active ingredient and chemical name of a non-chlorine shock treatment or non-chlorine oxidizer. See Non-Chlorine Shock.

SODIUM SULFITE: A chemical that can be used to neutralize chlorine or dechlorinate pool water.

SODIUM TETRABORATE: New technology that renders algae incapable of processing carbon dioxide, which they need to live.

SODIUM THIOSULFATE: A chemical that can be used to neutralize chlorine or dechlorinate pool water.

SOFT WATER: Water that has a low calcium and/or magnesium content. Soft water can result in the etching of the pool's surfaces, and should be increased with calcium chloride.

SOLAR COVER: A floating pool cover that increases the water temperature by absorption and transmission of solar radiation. It also reduces evaporation and pollution from the environment.

SOLAR HEATING SYSTEM: A system that consists of panels through which the pool water passes to increase its temperature by using the sun's heat.

SOLAR SYSTEM: Black mats of miniature plastic tubes through which water is pumped, absorbing the heat as it passes through. These mats are roof mounted with up & down plumbing connecting it.

SOLID COVER: These are usually made of some form of plastic or vinyl and are secured around the edges either by aqua bloks or similar weight or the edges attach to anchors set in the concrete or wood deck.

SOURCE: Refers to the origination of electrical power. The source for your filter pump (load) is probably a timer clock.

SPA: A filtered, hot water vessel with hydrotherapy jets and air induction. Can be portable or installed permanently. Jacuzzi is a brand name.

STABILIZED CHLORINE: A family of organic chlorine compounds that contain stabilizer (cyanuric acid or iso-cyanuric acid) to protect the chlorine from the degrading UV rays in sunlight. Most common types are dichlor and trichlor. The granular form is dichlor and the tablet or stick form is trichlor.

STABILIZER: See Cyanuric Acid. Stabilizers, also called conditioners, can be added directly to your pool to extend your chlorine efficacy. Cyanuric acid is already added to certain "stabilized" products such as Trichlor tablets and Sodium Dichlor.

STAIN INHIBITOR: Also called a Sequestering or Chelating Agent. A chemical that will combine with dissolved metals in the water to prevent the metals from coming out of solution and so avoiding discoloration of the water or stains.

STAIN: A discoloration or a colored deposit on the walls or bottom of a swimming pool. Stains are usually the result of metals such as iron, copper or manganese in the water. The stains may be green, gray, brown or black. They may discolor the water without affecting the clarity. Sometimes a sequestering agent, chelating agent or commercial stain-remover may remove them. If that doesn't work, the easiest way to remove the stains is to drain and acid wash the pool.

STRAINER BASKET: The second line of defense is a basket at the pump. The holes in this are smaller than those in a skimmer basket, and prevent the pump impeller from clogging up.

SUCTION SIDE: The plumbing prior to and carrying water to the pump. This side is under vacuum pressure.

SUPERCHLORINATION: Applying 7 10 times the normal amounts of chlorine to the pool as an added "boost" for contaminant removal. Some refer to super chlorinating as being less than shocking, in that breakpoint thresholds are not reached, or the terms may be used synonymously.

SUSPENDED SOLIDS: Insoluble solid particles that either float on the surface or are in suspension in the water causing cloudiness. They may be removed by filtration, but if the particles are too small a flocculent or coagulant is necessary to enable the filter to trap them.

TDS: See Total Dissolved Solids

TEE: A plumbing fitting used to bring two pipes together into one, or vice versa.

TEST KIT: A manual or electrical device used to measure specific chemical residuals, levels or demands in pool water. Kits usually contain reagents, vials, titrants and color comparators for the tests. The most common tests are: pH, free available chlorine, combined chlorine, total alkalinity, calcium hardness, cyanuric acid and metals.

TEST STRIPS: Small plastic strips with pads attached that have been impregnated with reagents to test pool water. The strips are dipped into the water and the resulting colors are compared to a color scale to determine the values.

TIME CLOCK: A mechanical device that controls the timed operation of your electrical equipment, primarily your filter and booster pumps.

TITRATION: A method of testing for total alkalinity, calcium hardness and acid/base demand by adding a titrant, drop by drop until a color change is observed.

TOTAL ALKALINITY: The total amount of alkaline materials present in the water, usually measured as carbonate alkalinity. It indicates the water's resistance to change in pH. Low total alkalinity causes pH bounce. High total alkalinity causes the pH to constantly rise.

TOTAL CHLORINE: The total amount of chlorine in the water. It is the sum of free available chlorine and combined chlorine.

TOTAL DISSOLVED SOLIDS (TDS): A measure of everything that has ever dissolved in the water; all the matter that is in solution. High TDS levels can oversaturate your water, causing all sorts of reactions.

TRICHLOR: A slow-dissolving, tablet or granular stabilized organic chlorine compound which provides 90% available chlorine and has a pH of 2.9. It must be dispensed using a floating feeder or an in-line chlorinator. Trichlor contains cyanuric acid that prevents the chlorine from being destroyed by the ultraviolet rays of the sun. When using trichlor, the cyanuric acid level needs to be checked regularly to avoid chlorine lock.

TURBIDITY: The cloudy condition of the water due to the presence of extremely fine particles in suspension that is able to pass through the filter. Adding a flocculent or coagulant will clump the particles together so they can be trapped in the filter.

TURNOVER: Also called Turnover Rate. The period of time, in hours, required by the pump to circulate the volume of water in the pool. Pool capacity in kilolitres divided by pump flow rate in kilolitres per hour (m3/h) will give the turnover rate in hours.

ULTRAVIOLET LIGHT TREATMENT: Using UV wavelength radiation to destroy contaminants in water. UV light is also used to create ozone molecules for the same purpose.

UNDERDRAIN: The lower collection system in a filter which directs filtered water back towards the pool. It also distributes water in reverse during backwashing. See laterals.

UNDERWATER LIGHT: A light fixture designed to illuminate a pool from below the water's surface.

VACUUM: A device that uses suction to collect dirt from the bottom and sides of a pool. Most common is a vacuum head with wheels that attaches to a pole and is connected to the suction line. Some automatic pool cleaners fall into this category.

VALVES: A device placed in the plumbing line which restricts or obstructs water flow to create desired hydraulics, or may permit flow in one direction only (as in a check valve).

VENTURI: Increasing water velocity by restricting pipe size.

VINYL LINER: One type of interior finish. The liner is draped over a sand or cementations floor, and locked into the top of the wall.

VIRUS: A pathogen capable of causing disease.

VISION SYSTEM: The technology which isolates nascent oxygen into a powerful sanitizing tool. See Cationic Sanitation.

WASTE GUTTER: The outer channel in a pool with 2 gutters. The inner channel (skimmer gutter) returns the water for filtration, while the outer one collects rain or washes water and diverts it to waste before it can enter the pool.

WATER CLARIFIER: See Coagulant/ Flocculent.

WEIR: The device in a skimmer that controls the amount of water coming into the skimmer, and keeps debris inside.

Winter Covers: A barrier to sun and debris, winter covers secure the pool from contamination. These are subdivided below.

ZEOLITE: An alternative to quartz or silica for use in sand filters. It is typically clinoptilolite, the specific zeolite suitable for pool water conditions. Zeolite can provide filtration down to 3 microns, is able to absorb heavy metals such as iron or manganese, and absorbs ammonia and nitrogen compounds. Zeolite can also absorb chloramines and is regenerated by washing in salt. Being less dense than quartz, 60% - 70% of the weight of quartz is used. Zeolite is also claimed to reduce backwashing by 50%.