Natare Terminology

AVAILABLE CHLORINE

see free available chlorine

ACID

a sour chemical substance containing hydrogen with the ability to dissolve metals, neutralize alkaline materials and combine with bases to form salts; acid is used to lower (decrease) pH and total alkalinity of swimming pool and spa water; examples are muriatic acid (hydrochloric) and dry acid (sodium bisulfate)

Acid DEMAND

amount of acid needed to lower pH to the proper level for pool water

ACID DEMAND TEST

reagent test usually used in conjunction with a pH test to determine the amount of acid needed to lower pH and total alkalinity levels

ACID RAIN

precipitation having an unusually low pH value (4.5 or lower) caused by absorption of air polluted by sulfur dioxide, carbon dioxide and nitrous oxide

ALGAECIDE

1. to kill algae; algaecides perform best as a backup to a routine sanitation program
2. help to kill airborne spores as they blow into the pool

ALGAESTAT

retards and prevents algae genesis and growth

Algae

1. microscopic plants deposited in pool or spa water by wind, rain and dust, they thrive in sunlight and warm water, clogging pool equipment and causing slippery surfaces and green water; there are 21,000 known species of algae
2. algae are not disease causing, but can harbor bacteria, and it is slippery
3. most common pool types are black, blue-green, green and mustard (yellow or drawn)
4. pink or red-colored algae-like organisms exist but are bacteria and not algae; maintaining proper sanitizer levels, shocking and superchlorination will help prevent algae occurrence

ALKALI

1. basic chemical that neutralizes acids by releasing carbonates and/or hydroxides
2. also called base
3. the opposite of acid

Alkaline

when pool water measures above 7.0 on the pH scale

Alkalinity

1. amount of carbonate, bicarbonate and hydroxide compounds in pool water
2. more commonly called total alkalinity
3. measure of the pH-buffering capacity of water
4. also called the water’s resistance to change in pH
5. one of the basic water tests necessary to determine water balance

Alum

Ammonia (NH3)

1. nitrogen-containing compound that combines with free chlorine to form chloramines; chloramines have a strong chlorine odor and can cause skin and eye irritation
2. introduced into the water by swimmers as waste (perspiration or urine) or by other means; quickly forms foul-smelling, body-irritating chloramine – a disabled, less- effective form of chlorine

ANTI-FOAM

chemical added to the water to make the sud or foam disappears; 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 superchlorination may help prevent foaming

ampere/hour (AH)

authorized release device

device that allows authorized persons to enter or exit monitored and controlled openings without triggering an alarm; the authorized passage release may be a keyed switch, a card reader, a digital code reader

automatic surge

device incorporated into a stainless steel perimeter

arc

electrical current through air or across the surface of an insulator associated with high voltage; usually occurs when a contact is opened, de-energizing an inductive load; arcing of a contact will limit its life

annunciator

audible and/or visual signaling device

ampere (amp)

unit of measurement for the rate of electrical current flow; one ampere is the current flowing thorough one ohm of resistance at one volt potential

American Wire Gauge (AWG)

standard system in the United States for designating wire size (diameter of metal)

American Society for Testing Materials (ASTM)

organization that tests materials and attempts to set standards on various materials for industry

alternating current (AC)

electric current that reverses its direction regularly and continually; the voltage alternates its polarity and direction of current flow negative to positive

airtraps

see interlock

adjustable

ability to change or alter time delay or other parameter by means of adjustment, such as a potentiometer, resistor, or switch

access control

means of influencing and regulating flow of persons through a door, entry and/or exit alarm

Automatic Surge

device incorporated into a stainless steel perimeter

ACRYLIC

thermoplastic sheet formed into a mold to make a spa or related equipment; it is first heated and then vacuumed onto the mold

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 BLOWER

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

AIR-RELIEF VALVE

1. brass or plastic, manually operated valve located at the top of a filter tank for relieving the pressure inside the filter and for removing the air inside the filter (called bleeding the filter)
2. sometimes called a pressure-relief valve

AUTOMATIC POOL CLEANER

device, which agitates or vacuum debris from the walls and floor of the pool automatically

AWS Systems

Access Equipment

variety of equipment designed to facilitate entrance and egress from a pool; may include ladders, lifts, steps or boards

Above-ground (On-ground) pools

pools that are portable and removable; a frame that is located entirely above ground and can be disassembled

Age group swimming

1. a structure of the U.S. Swimming organization where children break up into groups according the their age and ability and work on swimming technique and endurance with the help of a trained coach
2. nationally recognized age groups are 10 and under, 11-12, 13-14, 15- 16, 17-18 and 15-18; local swim meets may include events for 8 and under

Anchor

last swimmer in a relay

BYPASS

1. 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
2. a controlled diversion

BACTERICIDE

kills bacteria; chlorine is a bactericide and germicide; silver "algaecides" are actually more bactericide, and are useful on pink "algae"

BAKING SODA

1. sodium bicarbonate
2. white powder used to raise the total alkalinity of pool or spa water without having much affect on pH

Balanced Water

BASE

see alkali

BASE DEMAND

see acid demand

Biguanide

BLEACH

BLUE FINGERNAILS

1. condition caused by too much copper not chlorine in the pool water; 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, pool walls
2. can also be caused by keeping the pH too low or misusing acid

Breakpoint Chlorination

process of adding sufficient free available chlorine to completely oxidize all organic matter and ammonia or nitrogen compounds; all chlorine added after that point is free available chlorine

BROMAMINES

1. by-products formed when bromine reacts with swimmer waste, nitrogen or fertilizer
2. active disinfectants that do not smell although high levels are body irritants
3. removed by superchlorination or shock treating
4. a combined bromine-ammonia molecule; unlike chloramines, which are strong smelling and offer no sanitizing properties, bromamine compounds continue to sanitize

BROMIDE

1. a common term for a bromide salt used to supply bromide ions to the water so they may be oxidized or changed into hypobromous acid, the killing form of bromine
2. used as a disinfectant

BROMINATOR

mechanical or electrical device for dispensing bromine at a controlled rate; most often a canister or floater filled with tablets of bromine

Bromine (BR2)

1. chemical used in various compound forms to sanitize pool and spa water
2. it forms hypobromus acid in water
3. available as a tablet or as sodium bromide, a granular salt
4. member of the halogen family
5. used as a sanitizer in spas, because of its resistance to hot water with rapid pH fluctuations

BUFFER

1. substance or compound that stabilizes the pH value of a solution
2. water’s resistance to change in pH

BUFFERING CAPACITY

BACTERIA

single-celled microorganisms of various forms, some of which are undesirable or potentially disease-causing; bacteria are controlled by chlorine, bromine or other sanitizing and disinfecting agents

brownout

low line voltage that can cause misoperation of and possible damage to equipment

breakdown voltage

voltage at which insulation between two conductors is destroyed

break

open an electrical circuit

BALANCED WATER

correct ratio of mineral content and pH level that prevents the water from being corrosive or scale forming

battery standby

means of automatically switching over to stored battery power during local primary power failure

Bather Load

number of people in a pool or spa at a particular time or during a specific period of time

BLOWER

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

BACKFILL

repositioning of the soil after construction of a pool

BACKFLOW

backing up of water through a pipe in the direction opposite to normal flow

Backstroke Flags

colorful vinyl pennants spaced and sized to meet competitive swimming requirements; generally placed five yards (short coarse) or five meters (long course) from the end of the pool; they enable backstrokers to execute a backstroke turn more efficiently by counting their strokes

Backwash

reversing flow of water through the filter to clean the elements and filter medium

Backwash Cycle

time needed to backwash (clean) the filter and its components using a reverse flow of water

BALL VALVE

device with a hollowed out ball inside which can be turned with an external handle to decrease or increase flow

BOOSTER PUMP

secondary to the filter pump, a booster pump is used to power an automatic pool cleaner such as Polaris or Letro

BTU

1. abbreviation for British Thermal Unit; the amount of heat necessary to raise 1 lb. of water 1 degree Fahrenheit
2. a unit of measurement for the use of gas by a gas appliance; pool heaters are rated by their consumption

Backstroke flags

see flags

Bulkhead

a wall constructed to divide a pool into different courses such as a 50-meter pool into two 25-yard courses

Block

starting platform

CYANURIC ACID

1. a granular chemical added to the pool water, which provides a shield to chlorine for protection from UV radiation, which disrupts the molecule, destroying its sanitizing ability
2. also called stabilizer conditioner

COAGULANT

see clarifier

COMBINED CHLORINE

see chlorine combined

CONTAMINANTS

any microparticle or organism, which reduces water clarity or quality, or presents health hazards

COPPER

effective algaestat and algaecide, copper as elemental is used in many pool products

COPPER ALGAECIDE

chemical compound that contains the element copper; 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 copper’s ability to kill algae; these special copper algaecides are called 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

Conditioned Water

CONDITIONER

see cyanuric acid

Corrosion

CHLORINE ENHANCER

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

CARBONATE

primary in the make up of total alkalinity and total dissolved solids

CHITIN

1. naturally occurring polymer found in the shells of crabs and lobsters
2. contained in the some proprietary pool products, chitin acts as a coagulant and flocculent for oils, metals and organic materials

CHELATE

(pronounced KEY-late)

1. process of preventing metals in the water from combining with other components in water to form colored precipitates that stain the pool walls and bottom or produce colored water
2. also called a sequestering agent

CHELATED COPPER

algaecides that contain a special ingredient to prevent the copper from staining the pool walls and bottom or producing colored water

CHELATOR

similar to sequestering agents, 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

Chemical Feeder

Chloramines

CHLORINATED

see isocyanurate

CHLORINATOR

mechanical or electrical device for dispensing chlorine at a controlled rate; most often a canister or floater filled with tablets of chlorine

Chlorine (Cl2)

1. most widely used bacteria-killing agent for pool water; organic chlorine is more suitable than inorganic for pool use because it is generally easier to use, does not affect water balance as much and is non-clouding
2. oxidizes ammonia and nitrogen compounds (swimmer and bather waste)
3. member of the halogen family of sanitizers, its use in swimming pools is in the elemental form of a gas, or as a liquid, granular or tablet compound

CHLORINE FREE AVAILABLE

see free available chlorine

CHLORINE combined

1. portion of total available chlorine left over when free available is subtracted
2. measure of chlorine that has already combined with other molecules or organisms, primarily chloramines

CHLORINE total available

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 DEMAND

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 GENERATOR

electrical device that generates chlorine from a salt solution in a tank or from salt added to the pool water

CHLORINE LOCK

term that implies that an over abundance of cyanuric acid (stabilizer or conditioner) in the water would cause the chlorine to be all "locked up;" this is not true

chlorine NEUTRALIZER

1. 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 pool water tests
2. sold as chlorine and bromine neutralizer, it is used to destroy excessive amounts of chlorine or bromine, so the high levels will not affect swimmers

CLORINE RISIDUAL

see residual chlorine

CLARIFIER

1. also called coagulant or flocculant
2. chemical compound used to gather (coagulate or agglomerate), or to precipitate suspended particles so they may be removed by vacuuming or filtration; there are two types

Calcium Chloride (CaCl2)

1. soluble salt added to pool water to raise the calcium hardness level
2. commonly used for snow melting

Calcium Hypochlorite CA(OCL2)

see hypochlorite

Calcium Hardness

CALCIUM CARBONATE (CaCO3)

crystalline compounds formed in swimming pool and spa water when the calcium, pH and total alkalinity levels are too high; once formed, the crystals adhere to the plumbing, equipment, pool walls and bottom; these crystals are better known as scale

current

flow of electrons through a conductor; current is measured in amperes

continuous duty locking unit

electric lock equipped with a heavy-duty solenoid that can be energized indefinitely

continuous duty

device or control that can operate continuously with no off or rest periods

continuity check

test performed on a length of wire or cable to determine whether the electrical current flows continuously throughout the length

continuity

state of being complete and uninterrupted, like a normally closed circuit

contacts

electrically conductive points, or sets of points, used to make or break an electrical circuit mechanically

connector

any device used to provide rapid connect/disconnect service for electrical cable and wire terminations

conduit

tube or trough for protecting electrical wires or cables

conductor

material with the ability to carry electric current; the term is also used for an electric wire

coil, electric

successive turns of insulated wire that create a magnetic field when an electric current is passed through them

CIRCUIT BREAKER

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

CHECK VALVE

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

circuit

path through which electrical energy flows

circuit, closed

1. electrical circuit in which current normally flows until interrupted by the opening of a switch or a switch-type electronic component
2. circuit or switch in which the contacts are closed during normal operation

circuit, open

1. electrical circuit in which current does not flow until permitted by the closing of a switch or a switch-type electronic component
2. circuit or switch in which the contacts are open during normal operation

closure

point at which two contacts meet to complete a circuit

code

see national electrical code

Cover, Thermal

cover that retains heat and prevents water evaporation

COVER, WINTER

cover that is secured around the perimeter of a pool, spa or hot tub that provides a barrier to bathers and debris when the pool, spa or hot tub is closed for the season

COVER, SOLAR

cover that, when placed on the water’s surface of a pool, spa or hot tub, increases the water temperature by absorption and transmission of solar radiation; reduces evaporation and prevents wine-borne debris from entering the water

COVER, HARD-TOP

cover used on pools, spas and hot tubs that rests on the lip (coping) of the pool or spa deck – not a flotation cover; used as a barrier to swimmers and bathers, and for maintenance and thermal protection

COUPLING

plumbing fitting designed to join two pieces of pipe

COPING

cap or top lip on the pool or spa wall that provides a finished edge around the pool or spa; it can be formed, cast in place or precast, or prefabricated of extruded aluminum or rigid vinyl; it may also be part of the system that secures a vinyl liner to the top of the pool wall

CLARITY

degree of transparency of waterCONDUIT

CIRCULATION SYSTEM

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

CENTRIFUGAL PUMP

pump consisting of an impeller fixed on a rotating shaft and enclosed in a casing or volute and having an inlet and a discharge connection; the rotating impeller creates pressure in the water by the velocity derived from the centrifugal force

CARTRIDGE FILTER

pool or spa water filter that uses a replaceable porous element made of paper or polyester

Code of Conduct

agreement signed by a swimmer prior to travel stating that the swimmer will abide by certain behavioral guidelines

Coping

deck tile, usually about one foot wide, at the edge of the pool

Course

designated distance over which the competition is conducted; standard is 25 meters for summer league meets, 50 meters for Olympic competition, and 25 yards for regular year-round and college competition

Cut

1. slang for qualifying time
2. time standard necessary to attend a particular meet or event

Circle Swimming

performed by staying to the right of the black line when swimming in a lane, to enable more swimmers to swim in each lane

Dry Acid

1. sodium bisulfate
2. lowers pH and total alkalinity to proper levels

DEFOAMING

see anti-foam

DICHLOR

1. common name for sodium dichlor
2. fast dissolving chlorine compound containing chlorine and cyanuric acid (stabilizer or conditioner); it has a neutral pH and is quick-dissolving, so it can be used for regular chlorination or superchlorination

DIFFUSER

see overdrain

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, Soft-Swim, ionizers and copper and silver algaecides

DIRT DEMAND

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

DISTRIBUTOR

see overdrain

DPD (Diethyl-P-Phenylene Diamine)

a test reagent used to measure the amount of available chlorine in pool water; measures both total and free chlorine

de-energize

to remove power

dynamic head

dry contact

metallic points making (shorting) or breaking (opening) a circuit; the switched circuit must have its own source of power and is merely routed through the dry contacts

double pole, double throw (DPDT)

1. switch or relay output contact form (2 form C) in which two separate switches are operating simultaneously, each with a normally open and normally closed contact and a common connection
2. used to make and break two separate circuits

door status switch (DSS)

used to monitor whether a door is in an opened or closed position

direct current (DC)

electrical current that travels in only one direction and has negative (-) and positive (+) polarity; it may or may not have an AC ripple component; DC sources that are unfiltered should be referred to as full-save or half-wave rectified AC

delay on make

see delay on energization

delay on energization

1. mode of operation relative to timing devices; delay begins when initiate switch is closed or on application of power to input
2. also called delay on make

delay on break

mode of operation relative to timing devices; delay begins when the initiate switch is opened (delay on break of initiate switch)

decibel (dB)

increment of measurement used to compare measured levels of sound energy (intensity) to the apparent level detected by the human ear; expressed as a logarithmic ratio (sound that has 10 times the energy of another sound is said to be 10 decibels louder; 100 times the energy is 20 decibels louder; 1,000 times the energy is 30 decibels louder; and so on); decibel levels are correctly expressed as the number of decibels at a measured distance from source of sound (for example,125 dB at 10 feet)

DECKS

areas immediately adjacent to a pool or spa that are specifically constructed or installed for use by bathers for sitting, standing or walking

D. E. FILTER (Diatomaceous Earth Filter)

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 takes the D.E. and deposits it on a grid; the D.E. then becomes the filter medium

DECK SURFACING

DIATOMACEOUS EARTH

1. also called D.E.
2. white poder composed of fossilized skeletons of one-celled 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

Diatomaceous Earth Filter

see D.E. Filter

DIFFUSER

1. porous plate, tube or other device through which air is forced and divided into minute bubbles for diffusion in the water
2. an over drain on a sand filter
3. used on a closed-face impeller on a pump to concentrate water flow to the center of the impeller

DISSOLVED SOLIDS

1. also called TDS or total dissolved solids
2. a measure of the total amount of dissolved matter in water; examples are calcium, magnesium, carbonates, bicarbonates, sodium, chlorides and metals; high levels can cause corrosion, colored water or salty taste; maximum level is usually 2500 ppm for pools; maximum level for spas is 1500 ppm over starting level

Diving Board

see springboard

Drain (vacuum to waste)

this useful setting allows you to vacuum large volumes of debris that would either clog the filter or pass through it because of its small size; dirt that is vacuumed passes right out the waste line; it is also the setting of choice when draining the pool or lowering the water level

DRAIN

1. plumbing fitting installed on the suction side of the pump in pools, spas and hot tubs
2. sometimes called the main drain, it is located in the deepest part of the pool, spa or hot tub, it is not a drain, such as a drain on a kitchen sink; main drains do not allow the water to drain to waste but rather connect to the pump for circulation and filtration

Distance

events over 400 meters/500 yards

Dual Meet

competition between two clubs

Dryland Training

training done out of the water that aids; enhances swimming performance

Drill

an exercise involving a portion or part of a stroke, used to improve technique

DQ

disqualification from an event

Divisionals

championship meet of the summer league season

DIVING BOARD

recreational mechanism for entering a swimming pool, consisting of a semi-rigid board that derives its spring from a fulcrum mounted below the board and attached to the deck

ELECTROLYSIS

1. electrochemical reaction causing a black stain normally found around metal fixtures or on the plaster; caused by two dissimilar metals being plumbed together or from an improper electrical grounding of pool equipment or lights
2. decomposition of water and other inorganic compounds in aqueous solution by means of electricity; chlorine generators use this principle to produce chlorine from salt in the water

ENZYMES

designed to break down and digest oils

EFFICACY

1. power to produce an effect
2. chlorine’s efficacy is affected by many factors, including the sun, water balance and the water’s chlorine demand

energize

to apply power

equalizer line

line from below the pool surface to the body of a skimmer, designed to prevent air being drawn into the filter when the water level drops below the skimmer inlet; operates automatically

EFFLUENT

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

plumbing fitting shaped at a 90-degree or a 45-degree angle usually made of metal, PVC or plastic

ESCUTCHEON PLATE

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

FREE Available CHLORINE

1. free chlorine in the pool or spa water that is available to sanitize or disinfect the water
2. hypochlorous acid, the chlorine in pool water that is not combined with ammonia or nitrogen and therefore available to kill bacteria entering the pool

FOAM

froth of bubbles on the surface of the water; usually from soap, oil, deodorant, hair spray, suntan oil, etc., that is shed into the water as swimmers enter

Flocculating Agent

see clarifier

FLOCCULATION

combination, agglomeration, aggregation or coagulation of suspended particles in such a way that they form small clumps or tufts (called floc)

FLOCCULANT

see clarifier

FLOC

clump or tuft formed when suspended particles combine with a flocculating agent

FOAMING

surface foam on water caused by high TDS levels

FILM-X

1. compound of citric acid used in cleaning plaster and other pool areas
2. safe replacement for muriatic acid

FILL WATER

used in filling or adding to the water level

fuse

protective device, placed in a circuit as a safeguard, that contains a strip of easily melted metal; when the current flow becomes too great, the metal melts, thus breaking the circuit

face piping

piping, with all valves and fittings, used to connect the filter system together as a unit

fail safe

see fail-unlocked

fail secure

see fail-locked

feet of head

basic measurement of pressure or resistance in a hydraulic system, which is equivalent to the height of a column of water that would cause the same resistance

fire door latch

latch that has a 1/4-inch throw and an anti-friction reactor

form c contact

switch mechanism that contains three terminals (normally open, common, and normally closed)

FIREMAN’S SWITCH

mechanical switch located inside the time clock, which opens a circuit and shuts off the heater 10 or 15 minutes prior to shutting off the water circulation pump, allowing the heater to cool down; this helps reduce lime buildup in the heat exchanger

Foot Bath

Flow Rate

volume of liquid flowing past a given point in a specific time period, expressed in gallons per minute or hour

Flow Meter

measuring device that determines the gallons per minute of water flow through a pool re-circulation system

FILTRATION RATE

rate of water pumped through a filter, in gallons per minute (gpm)

FIBERGLASS

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 pools, spas and related shapes

Filter

mechanical device for straining suspended waste particles from the pool as water circulates through a porous substance called a filter medium; refers to the complete mechanism including all components; the three types of filters used in pools and spas are sand, cartridge and D.E. (diatomaceous earth)

FILTER AID

chemical compound added to the water or to the filter that allows the existing filter to become more efficient; examples are alum, water clarifiers and D.E. (diatomaceous earth)

FILTER AREA

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

FILTER CARTRIDGE

replaceable porous element made of paper or polyester used as the filter medium in cartridge filters

FILTER CYCLE

1. operating time between cleaning or backwashing cycles of a filter
2. amount of time the filter has water flowing through it each day expressed in hours

Filter Element

porous component in the filter tank that removes particles and other suspended wastes from water before its re-circulated back to the pool

filter latErals

see underdrain

FILTER MEDIUM

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

FILTER POWDER

common name for diatomaceous earth (D.E.), used as the filter medium in a diatomaceous earth filter

FILTER PUMP

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 used to support the filter medium; usually used with rapid-rate sand filters

Filter Sand

sharp silica or quartz particles graded for uniform size and used as a filter medium

FILTER SEPTUM

portion of the filter element consisting of cloth, wire screen or other porous material on which the filter medium or filter aid is deposited; nylon grid on a D.E. filter is the septum

Face Piping

piping, with all valves and fittings, which is used to connect the filter system together as a unit; this includes all valves and piping necessary for the filter plant to perform the functions of filtering or backwashing, either by the plant as a whole or any unit operating singly

Flags

1. colorful vinyl pennants spaced and sized to meet competitive swimming requirements; generally placed five yards (short course) or five meters (long course) from the end of the pool
2. enables backstroke swimmers to execute a backstroke turn more efficiently by counting their strokes

Finals

championship heat of an event in which the top six or eight swimmers from the preliminaries compete

Failed Swim

where a meet calls for proof of a time standard and the swimmer fails to meet that standard in a particular race

False Start

swimmer moving before the start of a race

gold

very soft ductile material that is noted for its resistance to corrosive metals; it is used primarily as a coating or plating

ground

conducting connection between an electrical circuit and the earth or other large conducting body, thus making a complete electrical circuit

ground, earth

portion of a circuit that is connected to a buried metallic object such as a grounding rod or water pipe

Gelcoat

colored polyester-resin liquid applied to a mold during the manufacturing of fiberglass pool or spa shells

GPD

gallons per day

GPH

gallons per hour

GPM

gallons per minute

GRAB RAIL

1. also called hand rail
2. tubular steel or plastic device that can be gripped by swimmers or bathers for the purpose of steadying themselves; usually located near the steps in the pool

GREEN HAIR

condition caused by too much copper, not chlorine in the pool water; 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 in turn will dissolve metals in the equipment; the dissolved metal (usually copper) then stains hair, fingernails and, eventually, pool walls; keeping the pH too low or misusing acid can also cause it

GROUND-FAULT CIRCUIT-INTERRUPTER

interrupts (de-energizes) the electrical circuit whenever it detects the presence of excess electrical current going to ground (usually 1/40th of a second and 5/1000th of an ampere)

Gunite

concrete and sand mixture sprayed onto a reinforced steel form to create a pool shell; dry mixture of cement and sand is mixed with water at the "gun or spraying device", hence the name

GUTTER

1. overflow trough at the edge of the pool through which floating debris, oil and other "lighter-than-weight" items flow; pools with gutters usually do not have skimmers
2. also called a perimeter or recirculation system

GAS VALVE

electronic valve in the pool heater that directs gas flow from the meter to the pilot and the burner tray

Gutter

overflow trough at pool edge; also called a perimeter or recirculation system

Hypochlorite

inorganic un-stabilized family of chlorine compounds used in various forms to provide chlorine for pool water; includes calcium hypochlorite, lithium hypochlorite and sodium hypochlorite

Hypochlorinator

feeder device that applies chlorine solutions to pool water at a controlled rate

Hypobromous Acid (HOBr)

most effective form of bromine in water for disinfecting

Hypochlorous ACID (HOCI)

active sanitizing form of chlorine

HALOGENS

chemical elements either individually or collectively that constitute Group VIIB of the Periodic Table of Elements

Hydroxyl Ion (OH-)

1. negatively charged particle of one oxygen and one hydrogen atom also called hydroxide
2. contributes to pH balance

HYDROGEN PEROXIDE

unstable, colorless, heavy liquid used as an oxidizing agent in pools and spas; may also be used to dechlorinate pool or spa water

Hydrogen Ion

positively charged nucleus of a hydrogen atom, which contributes to the acidity of pool water

HYDROGEN

1. lightest chemical element
2. component of water
3. frequent product of many chemical reactions; pH is a measure of hydrogen in its ionic form in water

Hydrochloric Acid (HCI)

1. strong acid used to control pH in pools and to acid wash pool interiors
2. also called muriatic acid

HERBICIDE

chemical compound used to kill or control plant growth or algae

HARDNESS

1. amount of calcium and magnesium dissolved in the water
2. "water" or "total" hardness refers to the total magnesium and calcium dissolved in the water; calcium hardness refers to just the calcium
3. measured by a test kit and expressed as ppm; proper range is 200 to 400 ppm

HARD WATER

1. water that is high in calcium hardness and other salts
2. resists soap being lathered

HORSEPOWER

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

Hydrotherapy Spa

unit primarily for therapeutic use to ease stress, muscle strains and other physical problems

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

HYDROSTATIC PRESSURE

force involving built up ground water, which creates upward pressure beneath the pool shell

HYDROJET

fitting in the pool or 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

Hot Tub

a circular, wooden vessel with the sides and bottom formed separately and joined together by hoops, bands or rods; filled with heated and circulated water

HEATER

fossil-fueled, electric or solar device used to heat the water of a pool, spa or hot tub

HEAT PUMP

using a cooling coil, it removes heat from the air while the condenser coil transfers it to the water being cycled through the pump

HEAT EXCHANGER

1. device located inside the heater providing for 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
2. 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

HAND SKIMMER

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

HAND RAIL

see grab rail

HEATS

see prelim

IONIZER

water-sanitation device that uses electricity to generate metal ions, which are dispersed in the water; it works by passing a low-voltage DC current through a set of metallic (usually copper and silver) electrodes placed in line with the circulation equipment; copper is an algaecide, while silver is a bactericide; does not remove swimmer waste

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

1. also called stabilized chlorine and chlorinated
2. family of chlorine pool sanitizers that contain conditioner (cyanuric acid or isocyanuris acid) to protect the chlorine from the degrading UV rays in sunlight; the most common types are sodium dichlor and trichlor; the granular form is dichlor, which is fast dissolving and can be used for regular chlorination or superchlorination by broad casing into the pool or spa; tablet or stick form is trichlot (which is usually used in a chlorine feeder – either the floating type or the in-line erosion type) used for regular chlorination only

input voltage

designed power source requirement needed by equipment in order to operate properly

inrush

initial surge of current through a load when power is first applied; lamp loads, inductive motors, solenoids, and capacitive load types all have inrush or surge currents higher than the normal running or steady state currents; resistive loads such as heater elements, have no inrush

Interlock

1. system of multiple doors with controlled interaction
2. also known as lighttraps, airtraps, mantraps, and sallyports

intermittent duty solenoid

solenoid designed to be energized for short periods; continuous operation may damage an intermittent duty solenoid

Influent

1. water flowing into a filter, pipe, pool, chemical feeder or other space; water going into the pump is called in influent, while water leaving the pump is called the effluent
2. the water coming into and up to the impeller from the suction lines; these pipes are under vacuum pressure

In-ground pools

are partially or completely installed in the ground

INLET

fitting in the pool or spa on the water return line from the equipment that water returns to the pool

IMPELLER

rotating member of a pump; its action creates the flow of water

IM

1. individual medley
2. event in which the swimmer uses all four strokes in the following order

JANDY VALVE

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

LITHIUM HYPOCHLORITE

1. dry, granular chlorinating compound with an available chlorine content of 35 percent;
2. rapid-dissolving
3. used to superchlorinate vinyl-liner pools, painted pools or fiberglass pools as well as spas and hot tubs

Liquid Chlorine

1. sodium hypochlorite (NaOCI) solutions
2. pool disinfectant

Liquid Acid

see muriatic acid

LANGELIER INDEX

see saturation index

line voltage

voltage existing in a main cable or circuit, such as at a wall outlet

line drop

voltage loss occurring between any two points in a power or transmission line; such loss is due to resistance, reactance, or leakage of the line

line supervision

electrical supervision of a wire run to detect tampering (a cut or shorted wire); usually requires a terminating element at end of monitored wire loop

load

any device that consumes electrical power; the amount of power required for operation of a circuit or motion is obtained that moves the bolt

load rating

control specification outlining the type of load, minimum and maximum currents, and the voltage

local alarm

visual or audible signaling device located at monitored door, window, or other opening

lock status sensor (LSS)

relay type to operate the LED with an SPDT switch to indicate low voltage and tampering of the lock face locally or to a remote monitoring location

line cord

cord, terminating in a plug at one end used to connect equipment or appliances to a power outlet

lighttrap

see interlock

light emitting diode (LED)

diode, solid-state device that gives off virtually heatless colored light when electric current is passed through it; LEDs are very efficient, long lasting and are often used for digital readouts and annunciators; common colors include red, green, and amber

LOAD

electric device, which consumes energy, placing a load on the source

Lumina System

LOW WATER SUCTION

1. influent fitting, typically low on the wall in the deep end of a vinyl liner pool
2. a cheaper alternative to a main drain

LOWER COLLECTION SYSTEM

see underdrain

LIGHT NICHE

area in a pool or spa that house the underwater light

Leisure Surfacing

LEAF BAGGER

device that attaches to a telepole and a garden hose; pressure from the garden hose creates a suction by which leaves and large debris are sucked into a large mesh bag

Leaching

process of extracting a mineral from plaster pool interiors or tannic acid from wooden hot tubs

LATERALS

1. elongated, capped plastic nibs at the bottom of a sand filter, which are slotted to allow for water passage while keeping the sand in the filter tank
2. see also underdrain

LADDER BUMPERS

rubber caps or inserts that protect the pool plaster or vinyl liner from the sharp steel ends of the ladder

LADDER

structure used for getting in and out of the pool; a double-access ladder straddles the pool wall of an aboveground pool; an in-pool ladder is located in the pool only

Lane Rope

floating markers attached to a line that stretches from the starting end to the turning end of the pool to separate each lane

lane line

a rope with buoys that extends across the pool is to section off the water into long straight "lanes" so that swimmers do not bump into one another

Lane

specific area in which the swimmer is assigned to swim

Lap Counter

1. set of plastic display numbers used to keep track of laps during a distance race
2. the person who counts for the swimmer stationed at the opposite end from the start

Lap swimming

designated time when swimmers may use the distance of the pool at their own pace

Leg

part of a relay event swum by one individual swimmer

Lifeline

rope line across a pool to designate a change in slope in the pool bottom, or the beginning of deep water; usually supported by regularly spaced floats

Long Course

pool 50 meters in length

Long Distance

1. any freestyle event over 1500 meters, normally conducted in a natural body of water, such as a lake, river or ocean
2. also known as marathon swimming

LSC

1. Local Swimming Committee
2. governing body for swimming on a local level

MURIATIC ACID

the liquid dilution of hydrochloric acid used to lower pH and alkalinity, and to remove mineral stains and scale; extremely caustic and corrosive

MICROORGANISM

tiny, living, breathing creature in your pool; the purpose of disinfectants is to remove such pathogenic (disease causing) organisms

MINERAL

any substance that is neither animal nor vegetable; such as calcium, manganese, magnesium, nickel, copper, silver, iron, cobalt or aluminum; their presence in high non-chelated concentrations can lead to stains and scale when conditions are right

MAGNESIUM HARDNESS

1. measure of the amount of magnesium dissolved in the water; part of total or water hardness
2. causes scale if levels are too high

make

to close or establish an electrical circuit

mother board

master printed circuit board used to interface activities of individual printed circuit boards and the devices being controlled or monitored; the mother board is usually located at the back of a control panel assembly; individual printed circuit boards plug into it

monitoring loop

continuous loop of wire starting at the control panel and running through switches in a system to indicate a breach of security through an open switch or a cut wire

momentary switch

spring-loaded contact that, when pressed, closes two contacts; when pressure is removed, contacts open

momentary loss of power

short interruption of power to the total equipment

momentary duty lock

electric lock equipped with a solenoid that is energized only momentarily

mode of operation

specified operational condition of a switch, lock, door system, etc.

millisecond

one one-thousandth (0.001) of a second

milliampere

one one-thousandth (0.001) of an ampere

maximum rating

absolute maximum condition in which a device is designed to operate; voltage, frequency, current, temperature, humidity, shock, and other parameters can be specified as maximum

mantrap

see interlock

maintained contact switch

switch designed for applications requiring sustained contact, but with provision for resting

MULTIPORT VALVE

1. 4 or 6 position valve combining the functionality of several valves into one unit, revolutionizing pool plumbing
2. also called a rotary-type backwash valve; water from the pump can be diverted for various functions by merely turning the valve handle; the water may be sent to waste, used for backwashing, bypassing the filter for maximum circulation, for normal filtration, filtering to waste (rinse), or the valve may be closed to not pass water; the pump must be off before changing a valve setting

Movable Bulkhead

a movable end wall that allows multipurpose usage

MOTOR

1. machine for converting electrical energy into mechanical energy
2. known as the dry end of the filter pump; it drives the impeller, which moves the water

Modular System

cellular hi-rate sand filtration system utilizing an expandable modular cell design for increased flow rates

MICRON

1. unit of length equal to 1 millionth of a meter
2. 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 D.E. (diatomaceous earth) filters have openings of 1 to 5 microns); a granule of table salt is between 90 to 110 microns

Membranes

Mechanical Systems

integrated equipment including filters, piping, valves, pumps, disinfecting units and automatic control systems

MECHANICAL SEAL

1. seal behind the impeller that prevents water from running out along the shaft of a motor
2. also called a pump seal

MARCITE

originally a brand name for a white plaster finish coat from 1/8-1/2-inch inch thick applied over the gunite or shotcrete

MANIFOLD

branch pipe arrangement that connects several input pipes into one chamber or one chamber into several output pipes; a filter manifold connects several input pipes from the filter sept back into one common pipe

MAIN DRAIN

see drain

masters swimming

structured and supervised swimming period, where groups of adults participate in a set program; techniques and drills are utilized to improve performance

Middle Distance

events 200-400 yards/meter in length

Meet

equivalent to a "game"

NASCENT OXYGEN

single oxygen atom, not yet bonded to anything; extremely powerful oxidizer when harnessed

NEUTRALIZER

chemical used to make chlorine or bromine harmless

NITROGEN

gas that causes algae to bloom and disables chlorine

NON-CHLORINE SHOCK

1. class of chemical compounds used to oxidize or shock the water (destroy ammonia, nitrogen and swimmer waste); they contain no chlorine or bromine and do not kill living organisms; swimmers may re-enter the water in only 15 minutes after adding a non-chlorine shock
2. granular form of potassium permonosulfate, used to oxidize materials such as microorganisms, contaminants or chloramines

National Electrical Manufacturers Association (NEMA)

organization known for its standardization of wire and cable specifications

noise

unwanted and/or unintelligible signals picked up on a cable circuit

normally closed (NC)

normally open (NO)

National Electrical Code (NEC)

NORYL

brand name for a thermoplastic resin used in the manufacture of certain pump components and various other pool equipment fittings

Negative Split

swimming the second half of the race equal to or faster than the first half

National Age Group Time Standard

1. time standards derived from the previous years’ results; broken down by age and sex as well as B, A, AA, AAA, AAAA divisions; these designations are and may be used for qualifying purposes; many LSCs have their own time standards

National Age Group Top 16

time standards set for both short and long course based on previous years’ achievements; only times meeting these standards may be submitted for consideration each year

Orthotolidine (OTO)

see DPD

OVER-ACID

incorrect term used to describe water that is acidic or water that has a pH lower than 7.2

OVERDRAIN

1. also called a diffuser or distributor
2. internal sand filter device that evenly distributes influent pool water over the sand filter bed

Oxidation

1. chemical process for removing irritating organic compounds from pool water;
2. rusting or corrosion process that occurs as metals weathers

Oxidizers

agent that helps eliminate organic waste from pool water

OZONATOR

gaseous molecule comprised of three atoms of oxygen; it is generated on-site from air or oxygen and used for oxidation of water contaminants

OZONE

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

Organic Chlorine

1. form of chlorine that contains carbon and hydrogen atoms
2. most common ones for pool use are sodium dichloroisocyanurate (also know as sodium dichlorostriazinetrione) in granular form and trichloroisocyanurate (also known as trichlorostriazinetrione) in compressed form

Ohms Law

In electrical systems, there is a relationship between current, voltage, and resistance. This is known as ohms law, and can be written in many different forms, but always boils down to V=IR, where V is voltage, I is current, and R is resistance.

operating voltage

1. voltage by which a system operates
2. nominal voltage with a specified tolerance applied; design voltage range necessary to remain within the operating tolerances; for example, for a system specified 120 volts +/-10 percent of nominal, 120 volts is the nominal voltage and the design voltage range is 108 to 132 volts AC

output voltage

designed power source produced by a power supply

On-ground pools

see above ground pools

ORP

1. exudation reduction potential
2. measurement of a body of water’s ability to oxidize contaminants; measured with an electrode and an electronic meter
3. an indication of the sanitizing level or degree of safety from disease in the water; measured in millivolts with the accepted minimum level being 650 mV (millivolt)

Official

a judge on the deck of the pool at a sanctioned competition who is there to enforce rules; there are stroke and turn judges, administrative officials, starters, timers and referees

open swimming

see recreational swimming

open water swimming

an organized swim event in the ocean, lake or river; distances tend to be longer

Precipitate

solid particles forced out of solution by a chemical reaction; they may settle to the bottom of the pool or remain suspended in the water

ppm

1. parts per million
2. unit of measurement used in chemical application; it indicates the amount, by weight of a chemical, in relation to one million parts by weight of water (examples

POTASSIUM Peroxymonosulfate

1. active ingredient and chemical name of a non-chlorine shock treatment or non-chlorine oxidizer
2. does not kill bacteria or algae, but it will oxidize or destroy ammonia, nitrogen and swimmer waste;
3. it has a low pH
4. does not increase chlorine or bromine levels the way that superchlorination does
5. reactivates bromine to its killing form, hypobromous acid

POLYMER

1. substance made of giant molecules formed by the union of simpler molecules; many water clarifiers are made from organic polymers; an example would be polymerized ethylene, called polyethylene
2. algaecide/algaestat made up of repeating polymer molecules; used for green algae and available in varying strengths

POTASSIUM PERMONOSULFATE

see non-chlorine shock

PHENOL RED

chemical reagent dye used to test for pH; it can measure pH from 6.8 to 8.4

pH

indicates the acidity or alkalinity of pool water; on a scale of 0 to 14, values below 7 are acidic, while values above 7 are alkaline; ideal pool pH is a reading of 7.4 – 7.6

printed circuit board

means of making electrical interconnections without using insulated wires; printed circuit boards provide a supporting and insulating medium for components and conductors in a form that is readily adaptable to machine assembly

potentiometer (pot)

variable resistor

primary

transformer winding that receives the energy from a supply circuit

PVC MEMBRANE LINER

Pump

motor-powered mechanical device that creates pressure and water flow to permit filtration, heating and water circulation; pools usually use a centrifugal-type pump

PVC

1. polyvinyl chloride
2. used to make flexible and rigid PVC pipe

PUSH-PULL VALVE

two-position valve used for backwashing sand or DE filters

Pump Strainer

lint and hair trap on the suction side of the pump to remove debris with a minimum of water flow restriction

PUMP CURVE

1. also called a pump performance curve
2. graph that represents a pump’s water flow capacity at any given resistance

PUMP CAPACITY

volume of liquid a pump is capable of moving during a specified period of time; usually gallons per minute (gpm)

Psi

pounds per square inch

PRESSURE SWITCH

used in pool heaters that opens when the flow rate is insufficient for safe heater operation; this disrupts the circuit in the heater, preventing it from firing

PRESSURE SIDE

1. return side of the plumbing
2. section from the pump impeller toward the pool

PRESSURE GAUGE

device indicating pressure in a filter system

Pressure Differential

difference in the amount of water pressure being exerted on two parts of a hydraulic system, such as the incoming vs. the outgoing water through a filter

PRESSURE CHECK

1. test for the rate of water flow
2. a test for leaks in plumbing by placing a line in question under pressure and waiting for the pressure to drop

PRECOAT

depositing diatomaceous earth (D.E.) onto the filter grids or elements

PLUNGER

sliding disc assembly that changes valve position in a push-pull valve

PLASTER

mixture of white cement and white marble dust used as an interior finish, which can be tinted and colored applied to gunite or shotcrete pools or spas

PETCOCK

manually operated faucet or valve for draining liquids or releasing air pressure; air-relief valve on a filter is an example

Permanent Medium Filter

uses sand or other medium that does not require replacement

Perimeter System

see recirculating system

PATHOGENIC ORGANISM

organism that causes disease

Pace Clock

large clock with a large second hand and a smaller minute hand, used to check pace or to maintain intervals in practice; may also be digital

Proof of Time

a requirement at some meets to make certain that all swimmers have legally met time standards for that meet

Prelims

1. preliminaries, also called heats or trial
2. races in which swimmers qualify for the championship and consolation finals in events

QUATERNARY AMMONIUM COMPOUND (QUATS)

chemical compounds of ammonia used as algaecide and algaestats

QUATS

see quaternary ammonium compound

Q-Time

qualifying time necessary to compete in a particular event and/or competition

RESTRICTED FLOW

condition preventing full flow of water; restriction on the suction side creates higher vacuum, (or suction) while on the pressure side creates higher pressure

RESIDUAL CHLORINE

1. amount of measurable chlorine remaining after treating the water with chlorine
2. amount of chlorine left in the pool or spa water after the chlorine demand has been satisfied

RESIDUAL BROMINE

amount of measurable bromine remaining after treating the water with bromine

Recirculate

this setting bypasses the filter, water coming into the multiport does a U-turn and heads back towards the pool; used only when the filter is broken or when adding specialty chemicals, which specify using this setting

REBAR

1. reinforcement bar
2. used to add strength to a concrete; after excavation of an in ground pool, a steel cage is formed out of re-bar, and the gunite shell is shot over and surrounding it

REAGENTS

chemical agents, dyes, indicators or titrants used in testing water balance

regulated power supply

power supply that provides a constant output regardless of input voltage variations

resistor

circuit element whose chief purpose is to oppose the flow of current

resistance

1. opposition to flow of an electric current (measured in ohms)
2. reciprocal of conductance

reset time

time required to return the output to its original condition

remote reset

switch located at a monitored opening; if a violation occurs, the alarm at the main control console cannot be turned off until the door is secured and the remote reset is activated; its purpose is to ensure the inspection of an opening that has been violated or left open

remote alarm

visual or audible signaling device used to signal violations at locations removed from the central control station or monitored openings; for example, a remote alarm may be placed on a roof, or at guard stations outside a building

relay

electrically controlled-device that opens and closes electrical contacts to effect the operation of other devices in the same or another electrical circuit

recycle time

rectifier

solid state electrical device that will allow current to flow in one direction only; it is designed to convert alternating current to direct current

rated voltage

maximum voltage at which electric component can operate for extended periods without undue degradation or safety hazard

reverse circulation

pool-water circulation system; water is taken from the surface of the pool and returned through inlets at the bottom of the pool

Residential

pools for home use rather than for public or commercial use

REGLET

.. A horizontal slot, formed or cut in a concrete, tile, masonry or block wall into which the top edge of Natatec PVC membrane or NataDek flooring or other material can be inserted and anchored.

Recreational Surfacing

Recirculating System

1. system of pipes, pumps, filters that allows water to be taken from the pool, filtered, treated and returned to the pool
2. also called a gutter or perimeter system

RATE OF FLOW

quantity of water flowing past a designated point within a specified time period, measured in gallons per minute (gpm)

Recreational swim team

swim team run by a club, or municipality or county

Relay

an event in which four swimmers compete together as a team to achieve one time

Referee

1. official who has the authority over all other officials at a meet
2. makes all final decisions and sees to the efficient running of the meet

Recreational swimming

1. also called open swimming
2. set time when swimmers of all ages may come to the pool; no lane lines are in the water; the water is "open"

sistema de visión

technology, which isolates nascent oxygen into a powerful sanitizing tool

Sodium Thiosulfate

1. chemical used to prevent false pH readings
2. added to the water sample to remove chlorine prior to testing

Sodium Sesquicarbonate

1. chemical mixture of equal parts soda ash and sodium bicarbonate used to increase pH and total alkalinity in pool and spa water
2. has a pH of 10.1

SODIUM SULFITE

chemical used to neutralize or de-chlorinate pool and spa water

SODIUM TETRABORATE

new technology that renders algae incapable of processing carbon dioxide, which they need to live

SODIUM CARBONATE

see soda ash

SOFT WATER

water that contains less than 100 ppm of calcium and magnesium; pools and spas should never be filled with soft water from a softener; water with less than 100 ppm of hardness should be increased to a minimum of 150-200 ppm using calcium chloride

STABILIZER

see cyanuric acid

STAIN

1. discoloration or a colored deposit on the walls or bottom of a swimming pool or spa; most often, stains are metals, such as iron, copper and manganese; may appear as green, gray, brown or black; may discolor the water; sometimes a sequestering agent or chelating agent will remove them; if not, usually an acid wash is necessary to remove them from the walls and bottom
2. stains are sometimes confused with scale

STAIN INHIBITOR

see chelate

STRAINER BASKET

second line of defense is a basket at the pump; holes are smaller than those in a skimmer basket, and prevent the pump impeller from clogging

STABILIZED CHLORINE

see isocyanurates

SUCTION SIDE

1. plumbing prior to and carrying water to the pump
2. under vacuum pressure

Super Chlorination

see shock treatment and breakpoint chlorination

SURFACTANT

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

SHOCK TREAT

practice of adding significant amounts of an oxidizing chemical (usually non chlorine oxidizers, such as sodium persulfate or potassium peroxymonosulfate) to the water to destroy ammonia and nitrogen compounds or swimmer waste

SHOCK

1. describes the products used in shocking, such as hypochlorites, potassium permonysulfate or hydrogen peroxide
2. act of bringing the sanitizer level up so high that breakpoint chlorination is reached; when breakpoint is reached, a "shock" is sent through the water, tearing apart molecules and slashing through cell walls

Sequestering Agent

see chelant

SEDIMENT

solid material settled out from the water

SCUM

1. extraneous or foreign matter, which rises to the surface of the water and forms a layer or a film
2. residue deposited on the tile or walls of the pool or spa

Scale

see calcium carbonate

Saturation Index

1. developed by Mr. Langelier
2. a numerical value used to indicate whether pool water is out of balance (either scale-forming or corrosive); four factors are taken into account

SANITIZER

chemical agent used to remove unwanted contaminants

SANITIZE

to kill all living things, including bacteria and algae

SODIUM CARBONATE (NaHCO3)

see soda ash

Shock Treatment

extra large dose of chlorine applied every two weeks or as needed to kill algae and eliminate chloramines in the water

SODA ASH

1. sodium carbonate (Na2CO3)
2. chemical used to counteract an acidic condition by raising pH

Sodium Bicarbonate (NaHCO3)

pool additive (baking soda) used to raise total alkalinity

SODIUM BISULFATE

see dry acid

Sodium Dichloroisocyanurate Na(C3N3O3Cl2)

1. granular organic chlorine that contains 62 percent available chlorine
2. also known as sodium dichloro-s-triazinetrione

SODIUM DICHLOR

see dichlor

Sodium Hypochlorite (NaOCI)

1. inorganic chlorine in clear, liquid form
2. provides 10 percent to 12 percent available chlorine; has a pH of 13 and requires that small amounts of acid be added to the pool to neutralize the high pH
3. does not contain conditioner or stabilizer to protect it from sunlight, but it is protected if stabilizer or conditioner is already in the water

SODIUM PERSULFATE

1. active ingredient and chemical name of a non-chlorine shock treatment or non-chlorine oxidizer
2. does not kill bacteria or algae, but it will oxidize or destroy ammonia, nitrogen and swimmer waster
3. does not increase chlorine or bromine levels the way that superchlorination does, so water may be entered in 15 minutes after addition
4. will not reactivate bromine

single pole, single throw (SPST)

switch with only one moving and one stationary contact, available either normally open (NO) or normally closed (NC)

switch, normally open

see normally opened

switch, normally closed

see normally closed

switch, momentary

see momentary switch

switch, maintained

switch that, when activated, maintains its activated position until it is inactivated

switches

devices that make or break connections in an electrical or electronic circuit; switches are usually manually operated but can also work by mechanical, thermal, electromechanical, barometric, hydraulic, or gravitational means

spike

momentary increase in electrical current; spikes can damage electronic equipment

solenoid

1. electromechanical device that operates the lockbolt
2. when electricity is applied, a mechanical device

single pole, double throw (SPDT)

switch or relay contact form (1 form C) that has a normally open and a normally closed contact with a common connection

short

security interlock

multidoor system in which all doors are normally closed and locked; releasing one door disables the releases for all other doors until the first door is closed and relocked

security condition sensor (SCS)

sensitive crystal relay to operate the LED with an SPDT switch to indicate low voltage and tampering of the lock face locally or to a remote monitoring location; primarily used in higher security applications

secondary

transformer winding that receives energy by electromagnetic induction from primary

Sally ports

see interlock

SKIMMER WEIR

1. 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
2. the weir also prevents debris from floating back into the pool when the pump shuts off

SILT

soil particles having diameters between 0.004 and 0.062 mm

Skimmer

SKIMMER BASKET

removable, slotted basket or strainer placed in the skimmer on the suction side of the pump; beneath the lid, the basket strains debris, as the first line of defense in filtering the water

SKIMMER NET

attached to a telescopic pole, a leaf rake is a very useful tool in keeping the pool clean

SLURRY

water or a liquid containing a high concentration of suspended solids

Solar Heating System

panels or coils of plastic or metal through which water passes to increase the temperature from 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 and down plumbing connecting it

SOURCE WATER

see make-up water

SPA

filtered, hot water vessel with hydrotherapy jets and air induction; can be portable or installed permanently

SPRINGBOARD

1. also called diving board
2. recreational mechanism for entering a swimming pool consisting of a semi-rigid board that derives its spring from a fulcrum mounted below the board and attached to the deck

SPS Systems

SURGE CONTROL GATE

device in a perimeter gutter system that controls the amount of water coming into the gutter from the weir openings in the face of the gutter

SURGE CONTROL TANK

1. large tank constructed near or immediately adjacent to the edge of the pool that incorporates a modulating valve on the main drain to maintain a normal operating level well below the level of the pool in quiescent operation
2. the difference between the pool level and the operating level in the surge tank is the surge capacity, which is normally required to be approximately 1 to 2 gallons per square foot of pool surface area

SURGE CONTROL WEIR

1. part of a stainless steel gutter that controls the operating level of the pool at quiescent (low or no-use periods) to ensure that adequate in-pool surge is available when swimmers enter the pool
2. eliminate the need for a surge control tank

SUSPENDED SOLIDS

insoluble solid particles that either float on the surface or are in suspension in the water, causing turbidity

Swimmer Load

the number of persons in the pool area at any given moment, or any stated period of time

SOURCE

the origination of electrical power; the source for a filter pump (load) is probably a timer clock

SAND

usually refers to the filter medium used by a sand filter; the grade most often specified by filter manufacturers is grade No. 20 with a particle size of 45 to 55 mm

SAND FILTER

filter using sand or sand and gravel as the filter medium; the pump diffuses water over the top of the sand bed, and forces it through the sand and into the laterals on the bottom

SEPTUM

portion of the filter element consisting of cloth, wire screen or other porous material on which the filter medium or filter aid is deposited; the nylon grid on a D.E. filter is the septum

SHOTCRETE

mixture of sand and cement sprayed onto contoured and supported surfaces to build a pool or spa; plaster is applied over the shotcrete; shotcrete is premixed and pumped wet to the construction site

synchronized swimming

Stroke & Turn Judge

Streamline

position used to gain maximum distance during a start and/or push off from the wall in which the swimmer’s body is as tight as it can be

Starter

the official at a meet responsible for starting each heat and calling the next heat to the blocks

Scratch

to withdraw from an event

Sprint

1. describes the shorter events (50 and 100)
2. in training, to swim as fast as possible for a short distance

Split

1. swimmer’s intermediate time in a race; splits are registered every 50 yards or meters and are used to determine if a swimmer is on record pace
2. under certain conditions, splits may also be used as official times

Short Course

a pool 25 yards or 25 meters in length

Set

combined group of drills to form a complete practice

Senior Swimming

program which provides fair and open competition in national swimming championships; it is designed to afford maximum opportunity for participation, provide an educational experience, enhance physical and mental conditioning and develop a pool of talented athletes for international competition; there are no age restrictions in senior competition

Seeding Times

time a swimmer uses to enter a meet; this time, which is written on the entry card, determines ones position and lane in a particular meet

Seed

to distribute the swimmers among the heats and lanes according to their times; in most cases, the fastest swimmers are in the final heat of an event

TURBIDITY

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 an organic polymer or alum, will coagulate the particles and make the filter more efficient

Trichloroisocyanurate (C3N3O3Cl3)

1. organic chlorine available in compressed tablets or sticks, containing 90 percent available chlorine
2. also known as trichloro-s-triazinetrione

TRICHLOR

1. slow-dissolving, tableted or granular, stabilized organic chlorine compound providing 90 percent available chlorine
2. used for regular chlorination but must be dispensed using a floating feeder or an in-line feeder (chlorinator)
3. contains an ingredient (cyanuric acid or stabilizer) that prevents the chlorine from being destroyed by the ultraviolet (UV) rays of the sun
4. pH of 2.8, and regular trichlor tabs should not be placed in the skimmer, as the low pH will corrode the metal components in the equipment

Total Dissolved Solids

1. measure of the total amount of dissolved material in the water; maximum amount in pools is 2500 ppm, maximum in spas is 1500 over starting TDS; the only way to effectively lower TDS is to drain part or all of the water and replace it
2. also called TDS

TOTAL CHLORINE

total amount of chlorine in the water; includes both free available and combined chlorine

Total Alkalinity

1. amount of alkaline bicarbonate in pool water
2. acts as a buffer to prevent fluctuations in pH

TANNIC ACID

see tannin

Titration

TEST STRIPS

small plastic strips with pads attached that have been impregnated with reagents that can be used to test pool water for residuals, levels, constituents or demands; usually dipped in the water, and the resulting colors of the pads are compared to a standard set of colors to determine concentration

TEST KIT

1. apparatus or device used to monitor specific chemical residuals, levels, constituents or demands in pool or spa water; kits usually contain reagents, vials, titrants, color comparators and other materials needed to perform tests; the most common pool and spa water tests are

TDS

Tannin

1. harmless organic chemical that is leached out of new redwood or cedar hot tubs and is present in some source water
2. also called tannic acid

transient voltage

1. refers to several parameters of a transient

transient

any increase or decrease in the excursion of voltage, current, power, heat and so forth, above or below a nominal value that is not normal to the source

transformer

1. electric device that changes voltage in direct proportion to currents and in inverse proportion to the ratio of the number of turns of its primary and secondary windings
2. see primary and secondary

TURNOVER

1. also called turnover rate
2. number of times a quantity of water equal to the total capacity of the pool passes through the filters in a stated time; usually in turnovers per day; pool 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

TIME CLOCK

mechanical or electrical device that automatically controls the periods that a pump, filter, heater, blower, automatic pool cleaner or other electrical devices are on or off

TELEPOLE

long-handled aluminum pole, which extends in length to which various pool-cleaning tools, such as brushes or vacuums, can be attached

TEE

Taper

final preparation phase prior to major competition; an older more experienced swimmer will shave his entire body to reduce resistance in the water

trial

see prelims

Tri-Meet

any competition between three clubs

Touch Pad

large sensitive board at the end of each lane where a swimmer’s touch is registered and sent electronically to the timing system

Time Trial

a time-only swim, not part of a regular meet

ULTRA VIOLET 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

1. lower collection system in a filter, which directs filtered water back toward the pool
2. distributes water in reverse during backwashing
3. also called filter laterals or lower collection system

UNDERWATER LIGHT

fixture designed to illuminate a pool or spa from beneath the water’s surface

U.S. swim team

age group program authorized by the U.S. Swimming organization

USA Card number

unique number assigned to a swimmer when they join United States of America Swimming

USA Swimming

1. United States of America Swimming, Inc.
2. national governing body for amateur competitive swimming in the United States

VISION SYSTEM

technology, which isolates nascent oxygen into a powerful sanitizing tool

volt (V)

1. unit of electromotive force
2. the difference of potential required to make a current of one ampere flow through a resistance of one ohm

voltage

term most often used (in place of electromotive force, potential, potential difference, or voltage drop) to designate electrical pressure that exists between two points and is capable of producing a flow of current when a closed circuit is connected between the two points

voltage drop

voltage loss experienced by electrical circuits due to two principal factors

volt/amp (VA) rating

VACUUM

1. one of several types of suction devices designed to collect dirt from the bottom of the pool; some discharge dirt and water into the filters, some discharge to waste, and some collect debris in a porous container, allowing water to return to the pool; some are self-propelled; others must be pushed or pulled across the pool
2. low-pressure condition created in the suction line
3. cleaning process of sucking leaves, algae and debris from the pool floor

VALVES

device placed in the plumbing line, which restricts or obstructs water flow to create desired hydraulics, or may permit flow in one direction only

VENTURI

1. fitting or device that consists of a tube constricted in the middle and flared on both ends; a fluid’s velocity will increase and a fluid’s pressure will decrease while passing through the constriction; 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
2. increasing water velocity by restricting pipe size

VINYL LINER

watt

common unit of electrical power; one watt is dissipated by a resistance of one ohm through which one ampere flows

wire

slender rod or filament of drawn metal

WATER CLARIFIER

1. also called coagulant or flocculants
2. a chemical compound used to gather (coagulate or agglomerate) or to precipitate suspended particles so vacuuming or filtration may remove them; there are two types

WEIR

see skimmer weir

Winterizing

procedure for protecting pools, spas and hot tubs from freezing conditions; includes physical and chemical protection

WATER CLARIFIER

1. also called coagulant or flocculants
2. a chemical compound used to gather (coagulate or agglomerate) or to precipitate suspended particles so vacuuming or filtration may remove them; there are two types:  inorganic salts of aluminum (alum) and other metals, and water-soluble organic polyelectrolytes

WEIR

see skimmer weir

Winterizing

procedure for protecting pools, spas and hot tubs from freezing conditions; includes physical and chemical protection

Warm Down

low intensity swimming used by swimmers after a race or main practice; it rids the body of excess lactic acid and gradually reduces heart rate and respiration

Warm Up

used by a swimmer prior to a main practice, set or race; loosens and warms muscles and gradually increases heart rate and respiration

Water Aerobics

see water exercise

Water Ballet

see synchronized swimming

water exercise

1. also called water aerobics
2. an exercise routine in the water

Water polo

high endurance sport with soccer-like strategy played in the pool; forward, backs and goalies try to throw a ball into the opponent’s net; players are not allowed to touch the bottom of the pool while playing

zone

1. specific area of protection
2. portion of a large protected area
3. power supply to operate equipment

Zone

1. specific area of protection
2. portion of a large protected area
3. power supply to operate equipment