FROG Water Care Experts Glossary of terms

A chemical compound that releases hydrogen ions into water, decreasing pH. Products like muriatic acid or Sodium Bisulfate (pH minus, down or decreaser) are used to lower pH and Total Alkalinity in swim spa water.

The amount of acid required to lower pH and Total Alkalinity of swim spa water to the correct level. Determined by the acid demand test.

A reagent test usually used in conjunction with a pH test to determine the amount of acid needed to lower pH and Total Alkalinity levels.

Precipitation having an unusually low pH value (4.0 or lower) caused by absorption of air polluted by sulfur dioxide, carbon dioxide and nitrous oxide.

The state of being acidic (corrosive), as opposed to being alkaline, measuring below 7.0 (neutral) on the pH scale.

A thermoplastic sheet formed into a mold to make a swim spa or related equipment. It is first heated then vacuumed onto the mold.

A description of unbalanced water that attacks and corrodes swim spa surfaces, fixtures and pipes.

A mechanical device that forces air through holes in the floor, bubbler ring or hydrotherapy jets in a swim spa.

A brass or plastic manually operated valve located at the top of a tank for relieving the pressure inside and for removing the air inside (culled bleeding). Also called a pressure relief valve.

Microscopic plant-like organisms containing chlorophyll that thrive in sunshine. They are present on vegetation, in the air, and in soils. Their microscopic spores are continually introduced into the swim spa by winds, dust storms, rain showers, etc. They grow rapidly in swim spa water when exposed to sunlight and temperatures above 40 degrees. If not controlled by chemical treatment, they form objectionable slime and odor, can interfere with proper filtration and greatly increase chlorine demand. Phosphates (fertilizers) in the water encourage their growth. There are 27,000 known species of algae. The most common in recreational water are black, blue green, green and mustard (yellow or drawn). Pink or red colored algae-like organisms exist but are bacteria and not algae. Yellow and black are hardest to kill. Maintaining proper sanitizer levels, shocking and superchlorination will help prevent its occurrence.

A chemical agent specifically designed and used to kill algae and prevent their recurrence.

A condition when the Water is above 7.0 on the pH scale.

The amount of bicarbonate, carbonate and hydroxide compounds present in the Water. Total Alkalinity is a measure of the water's ability to resist changes in pH. Total Alkalinity is one of the basic water tests necessary to determine water balance.

An aluminum sulfate compound, commonly called Floc. Used to help clarify water. Causes small particles to join together so that they can be trapped in the filter. Alum lowers the pH of the water.

See Alum

Introduced into the water by swimmers as waste (perspiration. urine. etc.) or by other means. Quickly forms foul smelling, body irritating chloramines - a disabled, less effective form of chlorine. See chloramines.

A chemical added to the water to make the suds or foam go away. These products do not remove the source of the sudsing. Most often, the water must be drained and refilled to remove the soaps, oils and other causes of foaming. Shocking and super chlorination may help prevent foaming.

A chemical compound used to remove iron stains from fiberglass and vinyl liner swim spas.

A swim spa maintenance system that will agitate or vacuum debris from the swim spa interior automatically.

A means of cleaning that reverses the flow of water through the filter, forcing dirt out a waste line. This is done by setting the backwash valve to the backwash position. Typical maintenance for sand and DE filters. NOTE: Never adjust the valve while the pump is running.

The time needed to backwash (clean) the filter and its components.

Invisible single cell organisms of various forms, some of which can cause infections or disease. Bacteria are controlled by chlorine or other sanitizing agents.

Water containing just the right amounts of TotaI Alkalinity, Total Hardness, pH and Total Dissolved Solids so as to prevent scale forming or corrosive tendencies.

Used to regulate the flow of water and to shut off skimmers, drains and other lines to vacuum or run a swim spa or other water feature.

The required amount of soda ash (or other pH increaser) to increase the pH level of swim spa water to the ideal range of 7.2 to 7.6.

A sanitizer that is part of a non-chlorine water treatment system. Most chemicals used with chlorine are incompatible with biguanide sanitizers and vice versa. The recommended shock for biguanide treated swim spas contains hydrogen peroxide.

An electrical device that produces a continuous rush of air to create the optimal bubbling effect in a spa, hot tub or swim spa. It is usually plumbed in with the hydrotherapy jets or to a separate bubbler ring.

A condition caused by too much copper in the swim spa water. Blue fingernails are not caused by chlorine. The copper may get into the water by the bad practice of placing trichlor tabs in the skimmer; this acidic product will cause low pH water, which will in turn dissolve metals in the equipment. The dissolved metal (usually copper) then stains hair, fingernails and, eventually, swim spa walls. It can also be caused by keeping the pH too low or misusing acid.

An elemental mineral used for conditioning water to provide clearer, more comfortable water

The process of adding sufficient chlorine to completely oxidize all organic matter, ammonia or nitrogen compounds. All chlorine added after that point is free available chlorine.

Distributing chemicals into a swim spa by scattering over the water surface.

By-products formed when bromine reacts with swimmer waste (perspiration, urine), nitrogen or fertilizer. Bromamines are active disinfectants and do not smell, although high levels are body irritants. Bromamines are removed by superchlorination or shock treating.

Abbreviation for British Thermal Unit. The amount of heat necessary to raise l lb. of water 1 degree Fahrenheit.

Chemicals that serve to prevent fluctuations in pH.

An arrangement of pipes, gates and valves by which the flow of water may be passed around a piece of equipment or diverted to another piece of equipment, a controlled diversion.

Scale that forms from calcium compounds when swim spa water is too alkaline, Total Alkalinity is too high or Total Hardness (also known as calcium hardness) is too high. These hard deposits accumulate on swim spa surfaces and equipment.

Also called "Calcium Up," is a soluble white salt used to raise the Total Hardness (also known as calcium hardness) of the swim spa water when required.

A measure of the level of calcium and magnesium in swim spa water. Helps determine how scaling or corrosive the water is. It is especially important to monitor Total Hardness (also knowns as calcium hardness) in swim spas with a plaster finish. The ideal range is from 200 to 400 ppm; the minimum level is 150 ppm. One of the basic water tests necessary to determine water balance.

The sanitizing or chlorinating agent using calcium as the carrying salt for application. It's a granular product that is not sun stable. It tends to increase the swim spa water pH. It is usually used for superchlorination. It usually contains 65% available chlorine

Filter with a pleated element that traps debris. Looks like a giant oil filter.

A mechanical device in a pipe that permits the flow of water or air in one direction only.

Copper algaecides that contain a special ingredient to prevent the copper from staining the swim spa walls and bottom or producing colored water.

(Pronounced KEY late) Also coiled sequester. A chemical that binds up metals. Used to prevent metal staining and colored water.

Any of several types of devices that dispense chemicals into the swim spa or swim spa water at a predetermined rate. Some dispense chlorine or bromine while others dispense pH adjusting chemicals.

Smelly chemical compounds formed when chlorine binds to the body waste swimmers bring into swim spa (for example, sweat and urine. Chloramines have an objectionable odor of "too much chlorine" and can irritate swimmers' eyes and skin. Cured by proper shocking.

A mechanical or electrical devise for dispensing chlorine at a controlled rate. Most often a canister or floater filled with chlorine tablets.

The most widely used bacteria killing agent for recreational water treatment. A sanitizer and an oxidizer. As a sanitizer it kills bacteria in swim spas. As an oxidizer it burns off organic matter and kills algae.

The amount of chlorine required to control bacteria, algae, and other contaminants in swim spa water. Once the chlorine demand is satisfied, the water will be in a sanitary condition until further contamination takes place.

A chemical compound that when used in conjunction with chlorine makes the chlorine perform better as an algaecide.

The purest form of chlorine, which can be applied to swim spas only by trained professionals. It is not an appropriate sanitizer for spas.

An electrical device that generates chlorine from a salt solution in a tank or from salt added to the swim spa water.

A term used to describe a condition where chlorine has slower killing speed on algae, bacteria and burning out organic matter. It is caused by over stabilization or excess Cyanuric Acid (CYA).

A chemical used to make chlorine harmless. Used in test kits to counteract the bleaching effect of the chlorine or bromine in order to increase the accuracy of swim spa water tests. Sold as chlorine and bromine neutralizer, it is used to control excessive amounts of chlorine or bromine, so the high levels will not affect swimmers.

The amount of chlorine that remains in the swim spa or spa water after the chlorine demand has been satisfied. See also Free Available Chlorine.

The flow of water in a swim spa. ideally the circulation should leave no dead spots (areas of stagnant water).

A chemical used to remove haze in the water Usually works by causing small particles to join together so the filter or vacuum can pick them up. Also called coagulant or flocculent. There are two types: inorganic salts of aluminum (alum) or water soluble organic polyelectrolytes.

A chemical compound added to water to gather suspended particles together for filtration. See Flocculating Agent.

A test where a reagent causes a change in color when reacting with the specified chemical. This color is then compared to a color standard chart.

Chlorine that is in combination with ammonia, nitrogen or other organic compounds. See Chloramines

Chemically, conditioner is Cyanuric Acid (CYA) (CYA) It slows down the degradation of chlorine in the water by sunlight. Minimum level is 10 ppm. Too much can reduce the effectiveness of chlorine. Conditioner does not protect bromine from sunlight.

The material that joins the swim spa to the deck. Made of concrete, aluminum, plastic, brick or wood. Commonly concrete on concrete swim spas and aluminum on vinyl swim spas.

One of nature's elements, it’s also used for various parts of equipment and plumbing in swim spas. Corrosive water caused by misuse of chemicals, improper water balance, or placing trichlor tablets in the skimmer can cause copper to be dissolved from the equipment or plumbing and deposit the precipitates on hair, fingernails or swim spa walls. High levels of copper can also cause green water. Copper is also used as an algaecide. Maximum level is about 0.2 ppm.

A chemical compound that contains copper. Copper sulfate was one of the original copper algaecides. Too much copper in the water can cause green colored stains. Newer copper algaecides contain an ingredient that prevents the copper from staining but does not affect the copper's ability to kill algae. These special copper algaecides are called chelated copper algaecides.

The etching, pitting or eating away of the swim spa, surfaces or equipment. Caused by improper water balance, misuse of acid or acidic products or from soft water.

A water condition of low pH (acid condition) that can corrode metal pipes, swim spa fixtures and pumps.

A plumbing fitting used to connect two pieces of pipe.

A cover used on swim spas that rests on the lip (coping) of the swim spa or spa deck - not a floatation cover. Used as a barrier to swimmers and bathers, and for maintenance and thermal protection.

A cover that, when placed on the water's surface of a swim spa, increases the water temperature by absorption and transmission of solar radiation; reduces evaporation and prevents wind borne debris from entering the water.

Also called conditioner and stabilizer, or CYA. Stabilizes chlorine. Can be part of the chlorine, as in stabilized chlorine or can be added separately if using unstabilized chlorine. Dichlor contains a high percentage of CYA. Helps prevent deterioration of chlorine from heat or sunlight. Avoid high levels (75 ppm or above), which can cause discoloration, odors and other problems. Recommended level = 2S ppm.

The area that surrounds the swim spa. A deck should drain well and be slip resistant.

Also called Anti Foam. A chemical that reduces and/or eliminates foam. It pops bubbles. Squirt it over the water surface.

The common name for sodium dichlor. A fast dissolving chlorine compound containing chlorine and Cyanuric Acid (CYA) (stabilizer or conditioner) It has a neutral pH and is quick dissolving

Eyeball type of device that attaches to the swim spa return so that the water can be directed a certain way.

Presence of unusual colors in the water, commonly clear green or brown.

See Total Dissolved Solids (TDS)

Technical name is Diethyl P Phenylene Diamine. A test reagent used to measure disinfectant levels such as free available chlorine and total chlorine.

Sodium Bisulfate added to water to lower pH or Total Alkalinity. Safer to handle than muriatic acid.

The water that flows out of a pump, filter or heater, usually on its way back to the swim spa. Water entering the pump is called “influent.”

The resulting color change in a test sample created when you add drops of a given reagent. The number of drops correlates with a measurement.

Break down oily, gooey substances and convert them to water and carbon dioxide.

A device used in some swim spas where the main drain line is plumbed into the skimmer. Varies the flow from skimmer and main line, usually adjusted before vacuuming

An ornamental shield, flange or border used around a pipe, plumbing fitting, grab rail or light.

A device in the circulating water line of the swim spa that provides a constant controlled source of sanitizer, usually in the form of chlorine tablets for the recirculating water.

A lighting system that has light generated at a remote source and transmitted along fibers.

Fine spun filaments of glass, which are available in a rope or mat form. When used in a process with polyester resins, catalysts and hardeners, can be formed or molded into swim spas and related shapes.

A device used to filter fine debris out of swim spa water.

A chemical compound added to the water or the filter that allows the existing filter to become more efficient. Examples are alum, water clarifiers and D. E.

The length of time between cleaning or backwashing the filter until it has to be done again.

The rate at which the water is traveling through the filter, expressed in U.S. gallons per minute (gpm) per square foot of filter area.

Added to water to coagulate particles that cause haze. See Alum or Clarifier.

The clump of tuft formed when suspended particles combine with a flocculating agent.

The quantity of water flowing past a designated point within a specified time, such as the number of gallons flowing post a point in 1minute abbreviated as gpm.

A froth of bubbles on the surface of water. Usually comes from soap, oil, deodorant, hair spray, suntan oil, etc., that is shed into the water as people enter.

Also called Chlorine Residual or Available Chlorine. The amount of active chlorine remaining in the water after the chlorine demand to control algae, bacteria, or other contaminants has been satisfied. Recommendations vary for swim spa type, swim spa usage patterns and swim spa water pH.

Ground fault circuit interrupter. A device intended to protect people. It interrupts (de-energizes) the electrical circuit whenever it detects the presence of excess electrical current going to ground.

A hollow, collapsible plastic fitting used to plug the skimmer. If ice forms in the skimmer the gizzmo can absorb the expanding ice. It's green and looks like a thermos bottle.

Abbreviations for gallons per day, gallons per hour, gallons per minute relating to flow rate.

Also called a handrail. A tubular steel or plastic device that can be gripped by people to steady themselves. Usually located near the steps in a swim spa.

This is caused by too much copper in the swim spa water. Green hair is not caused by chlorine. Copper may get into the water by the bad practice of placing trichlor tablets in the skimmer. This acidic product will cause low pH water, which will in turn dissolve metals in the equipment. The dissolved metal (usually copper) then stains hair, fingernails and eventually, swim spa walls. it can also be caused by keeping the pH too low or misusing acid.

See Grab Rail.

A screen attached to a frame that is then attached to a telepole used to remove large floating debris, such as leaves and bugs, from the water's surface.

Cloudiness in the water caused by very small floating particles. Also known as “Turbidity.”

A device located inside the heater that provide the transfer of heat from the heat source to the water. This is usually a series of metallic tubes with fins located just above the flames.

A fossil fueled, electric or solar device used to heat swim spa water.

Swim spa water containing high levels of dissolved minerals. High levels of dissolved solids may cause water to have a "flat" or ''salty" taste and cause water to appear dull or "dead." Swim spas with water three to five years old, or those containing water with solids higher than 3,000 ppm should be partially drained or diluted with fresh water.

The work done per unit of time;1 horsepower equals 33,000 foot pounds of work per minute or approximately 746 watts. Motors for pumps are rated in horsepower.

A fitting in the swim spa on the water return line from the equipment that blends or mixes air and water, creating a high velocity turbulent stream of air enriched water.

See Muriatic Acid.

The lightest chemical element. A component of water, and a frequent product of many chemical reactions. pH is a measure of hydrogen in its ionic form in water.

An unstable, colorless, heavy liquid used as a bleach in industry and an antiseptic in households. It is used as an oxidizing agent in swim spas, especially with biguanide systems. May also be used to dechlorinate swim spa water.

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 (liquid chlorine).

The “heart" of the centrifugal pump. Rotating veins create the suction flow of the water into the pump. Pumps do more pushing than pulling.

The water entering the pump, the filter or other equipment of space. Water going into the pump is called influent, while water leaving the pump is called effluent.

A fitting in the swim spa on the water return line from the equipment that water returns to the swim spa. Usually the last thing on the return line.

A water sanitation device that uses electricity to generate copper and/or silver ions, which are dispersed in the water. It works by passing a low-voltage DC current through a set of metallic electrodes placed in line with the circulation equipment. The copper is an algaecide, while the silver is a bactericide. It does not remove swimmer waste.

Iron in water can cause the water to be brown or green colored. This can be controlled adding a sequestering or chelating agent. Water can be tested with an iron test kit.

A formula developed by Dr. W.F. Langelier to determine the scale forming or corrosive tendencies of water.

Similar to a surface skimmer but has a bag for picking up leaves.

Powered by a garden hose, not the swim spa's vacuum system. Debris is swirled into a nylon bag on top of the leaf vacuum.

See Muriatic Acid.

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, and inconvenient to handle and apply. Should not be confused with Chlorox

A granular form of chlorine or pressed into slowly dissolving tablets known for its tendency to dissolve quickly with 35% available chlorine.

A measure of the amount of magnesium dissolved in the water. It is a part of Total Hardness and causes scale if levels are too high.

The part of the swim spa that provides water circulation and is located in the center of the deep end on the swim spa bottom. Water Can be removed from the swim spa through the main drain.

This is sometimes called "tap" or “refill" water. It is the water used to replace water lost to evaporation, splash-out, leaks or bather drag out in the swim spa.

A unit of length equal to l millionth of a meter or .000394 of an inch. 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 10 microns; and Diotomaceous Earth (D.E) filters have openings of l to 5 microns. Without magnification, people can see objects about 35 microns or larger. A granule of table salt is between 90 to 110 microns.

Any substance that is neither animal nor vegetable. It is any class of substances occurring in nature. usually comprised of inorganic substances, such as quartz or feldspar, of definite chemical composition and definite crystal structure. It sometimes includes rocks formed by these substances. Ground water dissolves these rock substances and the dissolved minerals are present in tap water. Depending on the kinds of rocks the water comes into contact with, the minerals dissolved in the water may be just a few or may be many. Total Hardness is mostly comprised of these mineraIs.

A lever controlled chamber with a number of settings to allow you to backwash.

A solution of 3l.45% Hydrochloric Acid, also called “liquid acid.” It is used to lower pH, Total Alkalinity and for various cleaning needs, and acid washing.

National Sanitation Foundation. A nonprofit, non-governmental organization that provides public health and safety related information to concerned consumers around the world

A chemical used to make chlorine or bromine harmless. Used in test kits to counteract the bleaching effect of the chlorine or bromine in order to increase the accuracy of swim spa water tests. Sold as chlorine and bromine neutralizer, it is used to control excessive amounts of chlorine or bromine, so the high levels will not affect swimmers.

A gas that causes algae to bloom and disables chlorine. An element that when combined with chlorine forms chloramines. Common in rainwater, cosmetics, oils, perspiration and urine. Maintaining proper chlorine levels will prevent nitrogen from becoming a problem. Superchlorination will remove nitrogen and its related compounds.

Refers to volatile, combustible and sometimes biodegradable chemical compounds containing carbon atoms bonded together with other elements. The principal groups of organic substances found in water are proteins, carbohydrates, fats and oils. Also see organic waste.

Debris such as microorganisms, perspiration, urine, etc. that needs to be oxidized (burned up) regularly to prevent haze, algae, chloramines, etc.

The burning off of organic compounds (swimmer waste), ammonia and nitrogen compounds. These organic compounds disable chlorine, are body irritants and have a foul smell. Removal is accomplished by superchlorination or by shock treating with a non-chlorine oxidizer.

A form of oxygen that disinfects and deodorizes. It is generated and entered into a swim spa by an Ozonator. Highly unstable and cannot be used to create a sanitizer residual.

Parts per million (ppm) is a way of expressing very dilute concentrations of substances; it means out of a million and is a way of expressing very dilute concentrations of substances. It usually describes the concentration of something in water or soil. One ppm or 1 ppm is 1 part in 1,000,000. One ppm is equivalent to 1 milligram of something per liter of water (mg/1) or 1 milligram of water.

A measure from 1-14 of how acidic or basic the water is. A pH of 7.0 is neutral. Swim spa water should be kept slightly basic with a pH of 7.2 - 7.8. A low pH indicates an acid condition, which causes swimmer discomfort and corrodes swim spa surfaces and equipment A high pH indicates a basic condition, which promotes scale formation and causes cloudy water.

Sodium Bisulfate, also called dry acid. Used to reduce pH and/or Total Alkalinity. Also called pH Down or pH Decreaser.

Sodium Carbonate or soda ash. Used to raise pH. Also called pH Up or pH Increaser.

A reagent as(dye) for measuring the pH of water in a range from 6.8 to 8.2. It changes color from yellow to purple as the pH goes from 6.7 to 8.2.

A mixture of white cement and white marble dust used as an interior finish, which can be tinted, colored or left white; applied to the gunite or shotcrete of a pool – generally not used to build a swim spa.

A substance made of giant molecules formed by the union of simpler molecules. Many water clarifiers me made from organic polymers. An example would be polymerized ethylene, called polyethylene.

Potassium peroxymonosulfate. The active ingredient and chemical name of a non-chlorine shock treatment or non-chlorine oxidizer. Does not kill bacteria or algae but it will oxidize or control ammonia, nitrogen and swimmer waste. It has a low pH and does not increase chlorine or bromine levels the way that superchlorination does, so water may be entered 75 minutes after addition. It will also reactivate bromine to its killing form, Hypobromous Acid.

Solid particles forced out of solution by a chemical reaction. They may settle to the bottom of the swim spa or remain suspended in the water giving the water a cloudy look.

The coating of Diatomaceous Earth on the grids of a DE filter at the beginning of each filter cycle.

A round dial located on the backwash valve or on top of the filter. Indicates in pounds per square inch (psi) the pressure inside the filter or other closed container. When the pressure reads 70 psi or more above the reading when the filter was last cleaned, that would indicate it is time to clean the filter again.

Filling the strainer or vacuum hose with water to help the pump push air out of the lines. If the pump won't prime, a full flow of water to the pump is being impeded by an air leak or restricted by clogged lines or baskets.

A motor-powered mechanical device that creates pressure and water flow by spinning an impeller to provide circulation through the filter and heater.

Chemical testing compounds that are used to test for Chlorine, Bromine, pH, Total Alkalinity, Total Hardness, etc.

The point at which the water returns to the swim spa after having traveled through the filter.

Type of filter that uses sand to clean the water.

A general term for a substance used as a disinfectant to kill bacteria und algae and oxidize organic contaminants. Generic names include Bromine, Biguanide and Chlorine.

Mineral deposits that form on swim spa or surfaces und equipment due to excessive calcium in the water when the pH level is high. Scale may appear as gray, white or dark streaks on the acrylic, fiberglass surfaces. It may also appear as a hard crust around tile.

The extraneous or foreign matter that rises to the surface of the water and forms a layer or a film there. It can also be residue deposited on the tile or walls of the swim spa. Sources of scum include soap, oil, deodorant, hair spray, suntan lotions and others.

The solid material settled out from the water.

A chemical that bonds with metals so that they can't cause staining or discoloration. See also Chelating Agent.

An oxidizer that burns off the organic waste that causes cloudiness and algae. It's a generic term for a chemical used to oxidize organic waste.

The practice of adding a significant amount of an oxidizing chemical (usually non chlorine oxidizers, such as sodium persulfate or potassium peroxymonosulfate) to the water to control ammonia, nitrogen compounds or swimmer waste.

Soil particles having diameters between 0.004 and 0.062 millimeters. Sometimes they may be too small to be trapped by the circulation system. In those cases, a clarifier or an alum product may be needed.

A system that uses silver ions to kill bacteria in water

A chemical substance used in swim spas as an herbicide or algaecide. Mainly used for killing black algae.

The white, box-like compartment on the side of the swim spa that automatically skims the top few inches of water, removing debris and oily films. Contains a removable basket that needs to be periodically cleared of debris.

Part of a skimmer that adjusts automatically to small changes in water level to assure a continuous flow of water to the skimmer. The small floating "door" on the side of the skimmer that faces the water over which the welter flows on its way to the skimmer. The weir also prevents debris from floating back into the swim spa when the pump shuts off.

A manually controlled valve with two settings used to direct swim spa water flow.

A method of lowering Total Alkalinity by pouring pH decreaser in one concentrated spot and turning off the filter.

Water or a liquid containing a high concentration of suspended solids. Diatomaceous earth (D.E.) is usually added to the filter as a slurry by mixing a small amount of D.E. in a bucket of water and then pouring the slurry into the skimmer with the filter on.

See Sodium Carbonate.

Baking Soda or Bicarb. The alkaline salt compound used to raise Total Alkalinity. Not to be used for increasing pH Also called Bicarb or Bicarbonate of Soda.

Dry Acid also called pH Down. Used to decrease the pH and/or Total Alkalinity of water.

A salt of bromine used to establish a bromine "bank" in swim spa water prior to beginning the use of bromine tablets.

Soda Ash. Used to increase water’s pH. Also called pH Up.

Also called Alkalinity Up or pH Stabilizer. Used to raise Total Alkalinity.

Otherwise known as common household bleach

Active ingredient and chemical name of a non-chlorine shock treatment or non­chlorine oxidizer. Does not kill bacteria or algae but it will oxidize or control ammonia, nitrogen and swimmer waste. Does not increase chlorine or bromine levels the way superchlorination does, so water may be entered 75 minutes after addition. It will not reactivate bromine.

A chemical mixture of equal ports soda ash and sodium bicarbonate used to increase pH and Total Alkalinity in swim spa. It has a pH of 10.1.

A chemical used to neutralize or dechlorinate swim spa water.

A chemical used to neutralize or dechlorinate swim spa water.

Water low in calcium and magnesium mineral content (Total Hardness) usually less than 100 ppm. Also, water that has gone through a water softener. Swim spas should not be filled with soft water from a softener. Water with less than 100 ppm of Total Hardness should be increased to a minimum of 150 - 200 ppm using calcium chloride.

A cover that, when placed on the swim spa water's surface, increases the water temperature by absorption and transmission of solar radiation; reduces evaporation and prevents wind born debris from entering the water.

Accessory tubes through which water is warmed by the sun and returned to the swim spa.

Also called "tap" water. It is the water used to fill or refill the swim spa.

Chlorine that contains Cyanuric Acid (CYA) (CYA) to protect chlorine from the degrading UV rays in sunlight. Most common types are sodium dichlor and trichlor.

A discoloration or a colored deposit on the walls or bottom of a swim spa. Most often, stains are metals such as iron, copper and manganese. They may appear as green, gray, brown or black and may even discolor the water. Sometimes a sequestering or chelating agent will remove them. If not, usually an acid wash is necessary to remove them from the walls and bottom. The metals get into the water because the pH was too low, or someone has added u low-pH chemical directly into the circulation system. Stains are sometimes confused with scale.

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 (precipitating or causing stains). May also be a chemical that removes dissolved metals from water.

A basket in front of the pump that keeps fine debris from reaching the pump's impeller area. Must be cleaned periodically. Sometimes called a "hair and lint trap."

Adding sanitizers in larger amounts than normal (5 - l0X normal dosage) to burn out organics, chloramines, etc. See Shock.

A plastic, flat mesh net skimmer used to scoop up and remove floating debris.

A soluble chemical compound that reduces the surface tension between two liquids. It is used in many detergents and soapy cleaning compounds.

Insoluble solid particles that either float on the surface or are in suspension in the water, causing turbidity, or a cloudy condition. They may be held in suspension by agitation or flow. They may be removed by filtration, but if the particles are too small, they may not be trapped by the filter. In these cases, a clarifier or alum may be needed to remove them.

A long handled aluminum pole that extends in length. Various swim spa cleaning tools, such as brushes or vacuums, may then be attached.

Chemically treated strips that have the appropriate amounts of reagents on them. Simply dip them into the water and read the reactions (the color on the strip). These strips may test free available and total chlorine, bromine, pH, Total Hardness, Total Alkalinity and Cyanuric Acid (CYA). These strips are not to be used to replace more accurate DPD test kits. They can be used in conjunction with more accurate kits. People who use FROG @ease products need to use FROG @ease Test Strips, which are made with a single color match Out Indicator to show when to replace the SmartChlor Cartridge. Other test strips will show Total Chlorine and Free Chlorine ranges that are different than the way FROG @ease Test Strips works, which causes confusion.

A generic term for a chemical commonly used to treat and prevent pink slime, water mold and algae.

A test used for acid and base demands, Total Alkalinity and Total Hardness. It creates an end point reaction by adding drops of the reagent to elicit a change in the sample’s color. The number of drops required correlates with the measurement. Sanitizer tests are available using this method

A measure of Total Alkaline substances dissolved in the water and of the water's ability to resist pH change (stability). If too low, the pH tends to bounce very erratically. If too high, pH resists adjustment and the water is more susceptible to scale and high pH. Recommended range is 80 - 150 ppm. See Alkalinity.

A measure of both "free chlorine" and "combined chlorine" in swim spa water.

A measure of the amount of dissolved matter in the water. A high level of solids (l500 ppm and higher) interferes with sanitizer effectiveness. Maximum amount in swim spas up to 3,000 gallons is 1500 ppm. The only way to effectively lower TDS is to drain part or aII of the water and replace it.

A measure of the level of calcium and magnesium in swim spa water. Helps determine how scaling or corrosive the water is. It is especially important to monitor Total Hardness in swim spas; the ideal range is from 200 - 400 ppm; the minimum level is 150 ppm. One of the basic water tests necessary to determine water balance.

A slow dissolving, tableted or granular, stabilized organic chlorine compound providing 90% available chlorine. Used for regular chlorination but must be dispensed using a floating feeder or an in line feeder (chlorinator). Trichlor contains an ingredient that prevents the chlorine from being controlled by the sun’s ultraviolet (UV) rays. Trichlor has a pH of 2.8. Trichlor tablets should not be placed in the skimmer.

The cloudy condition of the water due to the presence of extremely fine particles in suspension that cannot be trapped by the filter because they are too small. Adding a clarifier, such as alum, will coagulate the particles and make the filter more efficient.

Used to test the amount of Cyanuric Acid (CYA) in the water. The reagent causes a cloudiness in the test water. Measurement is obtained by comparing the test water's visibility (the degree of clarity of a dot in the test vial) to the test manufacturer's chart.

The period of time (usually in hours) required to circulate a volume of water equal to the volume of water contained in the swim spa. For example, swim spa capacity in gallons, divided by pump flow rate in gallons per minute (gpm). divided by 60 minutes in 1 hour, will give hours for 1 turnover.

Chlorine that does not contain Cyanuric Acid (CYA). Unstabilized chlorine is susceptible to degradation by the sun’s ultraviolet (UV) rays.

Any number of devices that use suction to collect dirt and debris from the bottom and sides of a swim spa. Most commonly, it is a vacuum head with wheels that attaches to a telepole and is connected to the suction line, usually via the opening in the skimmer. It must be moved about manually, and debris is collected in the filter. See also Automatic Swim Spa Cleaner.

Used to vacuum debris from the floor and slopes of the swim spa. It attaches to the vacuum head on one end and to the vacuum plate on the other.

Provides a vacuum sealed connection for the vacuum hose, allowing debris to be caught in the skimmer basket rather than the pump strainer basket.

A fitting that consists of a tube constricted in the middle and flared on both ends. While passing through the constriction, a fluid's velocity will increase while its pressure will decrease. Placing a tube or pipe at the constriction point creates a vacuum. Fluid or air can then be drawn in through the tube. A hydrotherapy jet draws air in and mixes it with the water using this principle.

Water Balance is reached when all elements (pH, Total Alkalinity, Total Hardness, total dissolved solids and temperature) are within their proper ranges.

A type of bacteria found in swim spa water. White-gray or pink in color, very slimy and difficult to eliminate.

The procedure to prepare for and leave swim spa water over the winter, as opposed to draining. Most swim spas are designed to be used in any climate year-round. However, if you don’t plan on using it during the coldest months of the year, winterizing will help protect components from freezing temperatures and keep the swim spa operating at peak energy efficiency. Winterizing includes chemical treatment of the water, plus physical protection of the swim spa and its equipment against freezing.