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
The
amount of acid required to bring high pH and total
alkalinity down to their proper levels. Determined by the
acid demand test.
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.
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.
ACRYLIC
A
thermoplastic sheet formed into a mold to make a spa or
related equipment. It is first heated and then vacuumed
onto the mold.
AIR
BLOWER
A
mechanical device that forces air through holes in the
floor, bubbler ring or hydrotherapy jets in a
spa.
AIR-RELIEF
VALVE
A
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). Sometimes called a
pressure-relief valve.
ALGAE
Microscopic
plant-like organisms that contain chlorophyll. Algae are
nourished by carbon dioxide (CO2) and use sunlight to
carry out photosynthesis. It is introduced by rain or
wind and grows in colonies producing nuisance masses.
Algae are not disease-causing, but can harbor bacteria,
and it is slippery. There are 21,000 known species of
algae. The most common pool types and black, blue-green,
green and mustard (yellow or drawn). Pink or red-colored
algae-like organisms exist but are bacteria and not
algae. Maintaining proper sanitizer levels, shocking and
superchlorination will help prevent its
occurrence.
ALGAECIDE
Also
called algicide - A natural or synthetic chemical
designed to kill, destroy or control
algae.
ALKALI
Also
called base - A Class of compounds which will react with
an acid to give a salt. Alkali is the opposite of
acid.
ALKALINITY
Also
more commonly called total alkalinity. A measure of the
pH-buffering capacity of water. Also called the water's
resistance to change in pH. Composed of the hydroxides,
carbonates and bicarbonates in the water. One of the
basic water tests necessary to determine water
balance.
ALUM
Any
one of several aluminum compounds used in pools to form a
gelatinous floc on sand filters or to coagulate and
precipitate suspended particles in the
water.
AMMONIA
Introduced
into the water by swimmers as waste (perspiration or
urine) or by other means. Quickly forms foul-smelling,
body- irritating chloramines - a disabled, less effective
form of chlorine. See chloramines or combined
chlorine.
ANTI-FOAM
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 superchlorination may help prevent
foaming.
ASCORBIC
ACID
A
chemical compound used to remove iron stains from
fiberglass and vinyl-liner pools.
AUTOMATIC
POOL CLEANER
A
pool maintenance system that will agitate or vacuum
debris from the pool interior
automatically.
AVAILABLE
CHLORINE CONTENT
A
term used or an index used to compare the oxidizing power
of chorine-containing products to gas chlorine. It
permits easy comparison of chlorine
compounds.
AVAILABLE
CHLORINE
The
amount of chlorine, both free and combined in the pool
water that is available to sanitize or disinfect the
water. Some- times called residual
chlorine.
BACKFLOW
The
backing up of water through a pipe in the direction
opposite to normal flow.
BACKWASH
The
process of thoroughly cleaning the filter by reversing
the flow of water through it with the dirt and rinse
water going to waste.
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.
BACTERICIDE
A
chemical or element that kills, destroys or controls
bacteria.
BAKING
SODA
Chemically
called sodium carbonate. It is a white powder used to
raise the pH of pool or spa water.
BALANCED
WATER
The
correct ratio of mineral content and pH level that
prevents the water from being corrosive or scale
forming.
BALL
VALVE
A
simple non-return valve consisting of a ball resting on a
cylindrical seat within a liquid
passageway.
BASE
Also
called basic - A class of compounds which will react with
an acid to give a salt. Base is the opposite of an acid.
See alkali.
BLEACH
This
term usually refers to liquid chlorine (sodium
hypochlorite 12% available chlorine). It is the same
chemical used in laundry bleach but pool chlorine is 12%
available chlorine while laundry bleach is about 5 to 6%
available chlorine.
BLOWER
An
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 in with the
hydrotherapy jets or to a separate bubbler
ring.
BLUE
FINGERNAILS
A
condition caused by too much copper in the pool water.
Blue fingernails are not caused by chlorine. The copper
may get into the water by the 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. It
can also be caused by keeping the pH too low or mis-using
acid.
BREAKPOINT
CHLORINATION
The
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
By-products
formed when bromine reacts with swimmer waste
(perspiration or 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.
BROMIDE
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. Used as a
disinfectant.
BROMINATOR
A
mechanical or electrical device for dispensing bromine at
a controlled rate. Most often a canister or floater
filled with tablets of bromine.
BROMINE
A
common name for a chemical compound containing bromine
that is ued as a disinfectant to destroy bacteria and
algae in swimming pools and spas. Available as a tablet
or as sodium bromide, a granular salt.
BTU
Abbreviation
for British Thermal Unit. The amount of heat necessary to
raise 1 lb. of water 1 degree Fahrenheit.
BUFFER
A
substance or compound that stabilizes the pH value of a
solution. It is also the water's resistance to change in
pH.
BYPASS
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.
CALCIUM
HYPOCHLORITE
A
compound of chorline and calcium used as a disinfectant,
sanitizer, bactericide, algaecide and oxidizer in
swimming pool and spa water. It is available as a white
granular material usually used for superchlorination or
it is available as tablets used in a feeder for regular
chlorination. It usually contains 65% available
chlorine.
CALCIUM
CARBONATE
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.
CALCIUM
CHLORIDE
A
soluble white salt used to raise the calcium or total
hardness level in the pool or spa.
CALCIUM
HARDNESS
The
calcium content of the water. Calcium hardness is
sometimes confused with the terms water hardness and
total hardness. Too little calcium hardness and the water
is corrosive. Too much calcium hardness and the water is
scale forming. One of the basic water tests necessary to
determine water balance. Minimum level is 150 ppm. Ideal
range is 200 to 400 ppm.
CARTRIDGE
A
replaceable porous element made of paper or polyester
used as the filter medium in cartridge
filters.
CARTRIDGE
FILTER
A
pool or spa water filter that uses a replaceable porous
element made of paper or polyester.
CENTRIFUGAL
PUMP
A
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.
CHECK
VALVE
A
mechanical device in a pipe that permits the flow of
water or air in one direction only.
CHELATE
(Pronounced
KEY-late) - also called sequester - It is the 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.
CHELATED
COPPER
Copper
algaecides that contain a special ingredient to prevent
the copper from staining the pool walls and bottom or
producing colored water.
CHEMICAL
FEEDER
Any
of several types of devices that dispense chemicals into
the pool or spa water at a predetermined rate. Some
dispense chlorine or bromine while others dispense
pH-adjusting chemicals.
CHLORINE
NEUTRALIZER
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 pool
water tests. 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.
CHLORAMINES
Undesirable,
foul-smelling, body-irritating compounds formed when
insufficient levels of free available chlorine react with
ammonia and other nitrogen-containing compounds (swimmer
and bather waste, fertilizer, perspiration, urine, etc.).
Chloramines are still disinfectants, but they are a much
weaker, ineffective form of chlorine. Chloamines are
removed by superchlorination or shock
treating.
CHLORINATOR
A
mechanical or electrical device for dispensing chlorine
at a controlled rate. Most often a canister or floater
filled with tablets of chlorine.
CHLORINE
A
term used to describe any type of chlorine compound used
as a disinfectant in swimming pool and spa water or to
kill, destroy or control bacteria and algae. In addition,
chlorine oxidizes ammonia and nitrogen compounds (swimmer
and bather waste).
CHLORINE
DEMAND
The
amount of chlorine necessary to oxidize all organic
matter (bacteria, algae, chloamines, ammonia and nitrogen
compounds) in the pool or spa water.
CHLORINE
ENHANCER
A
chemical compound that when used in conjunction with
chlorine makes the chlorine perform better as an
algaecide.
CHLORINE
GENERATOR
An
electrical device that generates chlorine from a salt
solution in a tank or from salt added to the pool
water.
CHLORINE
LOCK
This
is a term that implies that an over-abundance of cyanuric
acid (stablizer or conditioner) in the water would cause
the chlorine to be all "locked up." This is not
true.
CHLORINE
RESIDUAL
The
amount of chlorine left in the pool or spa water after
the chlorine demand has been satisfied.
CLARIFIER
Also
called coagulant or flocculant - A chemical compound used
to gather (coagulate or agglomerate), or to precipitate
suspended particles so they may be removed by vacuuming
or filtration. The are two types; inorganic salts of
aluminum (alum) or water-soluble organic
polyelectrolytes.
CLARITY
The
degree of transparency of the water.
COAGULANT
An
organic polyelectrolyte used to gather (coagulate)
suspended particles in the water.
COMBINED
CHLORINE
Undesirable,
foul-smelling, body-irritating compounds formed when
insufficient levels of free available chlorine react with
ammonia and other nitrogen-containing compounds (swimmer
and bather waste, fertilizer, perspiration, urine, etc.).
Combined chlorine is still a disinfectant, but it is a
much weaker, ineffective form of
chlorine.
CONDITIONER
Chemically,
conditioner is cyanuric acid. It slows down the
degradation of chlorine in the water by sunlight. Minimum
level is 10 ppm. Too much does not slow down chlorine
activity or effectiveness. Conditioner does not protect
bromine from sunlight.
COPING
The
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.
COPPER
One
of nature's elements, it is used for various parts of
equipment and plumbing in swimming pools and 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 pool walls. High levels of copper also
cause green water. Copper is also used as an algaecide.
Maximum level is about 0.2 ppm.
COPPER
ALGAECIDE
A
chemical compound that contains the element 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 copper's ability to kill algae. These special
copper algaecides are called chelated copper
algaecides.
CORROSION
The
etching, pitting or eating away of the pool or spa or
equipment. Caused by improper water balance, misuse of
acid or acidic products or from soft
water.
COUPLING
A
plumbing fitting that is used to connect two pieces of
pipe.
COVER,
HARD-TOP
A
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.
COVER,
SOLAR
A
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 wind-born debris from entering
the water.
COVER,
WINTER
A
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.
CYANURIC
ACID
Also
called conditioner and stabilizer. Chemically,
conditioner is cyanuric acid. It protects chlorine in the
water from being destroyed by sunlight. Minimum level is
10 ppm. Too much does not slow down chlorine activity or
effectiveness. Does not protect bromine from
sunlight.
D.
E. FILTER
Diatomaceous
Earth Filter - A filter designed to use diatomaceous
earth (D.E.) as the filter medium. The D.E. is added
through the skimmer with the pump on, which takes the
D.E. and deposits it on a grid. The D.E. then becomes the
filter medium.
DECKS
Those
areas immediately adjacent to a pool, spa or hot tub that
are specifically constructed or installed for use by
bathers for sitting, standing or walking.
DEFOAMER
Also
called anti-foam - 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 superchlorination may
help prevent foaming.
DIATOMACEOUS
EARTH
Also
called D.E. - A white powder 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.
DICHLOR
The
common name for sodium dichlor. A 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
A
porous plate, tube or other device through which air is
forced and divided into minute bubbles for diffusion in
the water. A diffuser can also be an overdrain on a sand
filter. A difuser is also used on a closed- face impeller
on a pump to concentrate water flow to the center of the
impeller.
DISINFECT
To
kill al pathogenic (disease-causing)
organisms.
DISSOLVED
SOLIDS
Also
called TDS or total dissolved solids - A measure of the
total amount of dissolved matter in water. Examples are
calcium, magnesium, carbonates, becarbonates, solium,
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.
DIVERTER
VALVE
A
plumbing fitting used to change the direction or redirect
the flow of water. Some diverter valves are used on
pool/spa combinations to allow the use of the spa and
then switch the flow back to the pool. A brand name
diverter valve is called an Ortega valve, which is
sometimes used to describe a diverter
valve.
DIVING
BOARD
A
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.
DPD
An
indicator reagent used for the determination of free and
total chlorine, bromine, ozone and other oxidizers in
water. Better than using OTO for chlorine because it
measures free chlorine.
DRAIN
This
term usually refers to a plumbing fitting installed on
the suction side of the pump in pools, spas and hot tubs.
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 to drain to waste but rather connect to the
pump for circulation and filtration.
DRY
ACID
Chemically,
sodium bisulfate. A dry white crystal that produces acid
when added to water. It is used for lowering pH and total
alkalinity. Safer to handle than muriatic
acid.
EFFLUENT
The
water that flows out of a pump, filter or heater, usually
on its way back to the pool or spa.
ELBOW
A
plumbing fitting shaped at a 90 degree or a 45 degree
angle usually made of metal, PVC or some other
plastic.
ELECTROLYSIS
An
electrochemical reaction causing a black stain normally
found around metal fixtures or on the plaster. It is
caused by two dissimilar metals being plumbed together or
from an improper electrical grounding of pool equipment
or lights. Electrolysis also means the 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.
EPA
Abbreviation
for the federal Environmental Protection
Agency.
ESCUTCHEON
PLATE
An
ornamental shield, flange or border used around a
plumbing fitting, grab rail or light.
FIBERGLASS
Finespun
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
A
device that removes undissolved or suspended particles
from water by recirculating the water through a porous
substance (a filter medium or element). The three types
of filters used in pools and spas are sand, cartridge and
D.E. (diatomaceous earth).
FILTER
AID
A
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
The
toal surface area of the filter medium that is exposed to
the flow of water from the pump, expressed in square
feet. Examples are: a 36 sq.ft. D.E. filter and a 100
sq.ft. cartridge filter.
FILTER
CARTRIDGE
A
replaceable porous element made of paper or polyester
used as the filter medium in cartridge
filters.
FILTER
CYCLE
The
operating time between cleaning or backwashing cycles of
a filter. Also the amount of time the filter has water
flowing through it each day expressed in
hours.
FILTER
ELEMENT
A
device within a filter tank designed to trap suspended
solids as water flows through it from the pool or
spa.
FILTER
MEDIUM
The
material used in the filter to trap suspended dirt
particles as the water is flowing through it. The
polyester or paper used in making a cartridge filter
element. The sand used in a sand filter. The D.E.
(diatomaceous earth) used in a D.E.
filter.
FILTER
POWDER
A
common name for diatomaceous earth (D.E.), used as the
filter medium in a diatomaceous earth
filter.
FILTER
ROCK
Graded,
rounded rock and/or gravel used to support the filter
medium. Usually used with rapid-rate sand
filters.
FILTER
SEPTUM
That
portion of tjhe 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.
FILTER,
SAND
A
type of filter media composed of hard, sharp silica,
quartz or similar particles with proper grading for size
and uniformity. The most common grade used is No. 20 in
sand filters.
FILTRATION
RATE
The
rate at which the water is travelling through the filter,
expressed in U.S. gallons per minute (gpm) per square
foot of filter area.
FIREMAN
SWITCH
A
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.
FLOC
(See
flocculation) - The clump or tuft formed when suspended
particles combine with a flocculating
agent.
FLOCCULATING
AGENT
Also
flocculant - A chemical substance or compound that
promotes the combination, agglomeration, aggregation or
coagulation of suspended particles in the
water.
FLOCCULATION
The
combination, agglomeration, aggregation or coagulation of
suspended particles in such a way that they form small
clumps or tufts (called floc).
FLOW
RATE
The
quantity of water flowing past a designated point within
a specified time, such as the number of gallons flowing
past a point in 1 minute - abbreviated as
gpm.
FOAM
A
froth of bubbles on the surface of the water. Usually
comes from soap, oil, deo- dorant, hair spray, suntan
oil, etc., that is shed into the water as swimmers
enter.
FREE
AVAILABLE CHLORINE
The
amount of free chlorine in the pool or spa water that is
available to sanitize or disinfect the water. Sometimes
called residual or available chlorine.
GELCOAT
A
colored, polyester-resin material applied to the surface
of a molded part. The gelcoat hardens to a smooth,
durable form and becomes an integral part of the
laminate. Fiberglass pools and spas have gelcoat
finishes.
GPD
An
abbreviation for gallons per day.
GPH
An
abbreviation for gallons per hour.
GPM
An
abbreviation for gallons per minute.
GRAB
RAIL
Also
called hand rail - A 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
A
condition caused by too much copper in the pool water.
Green hair is 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 in turn will dissolve metals in the
equipment. The dissolved metal (usually copper) then
stains hair, fingernails and, eventually, pool walls. It
can also be caused by keeping the pH too low or misusing
acid.
GROUND-FAULT
CIRCUIT INTERRUPTER
Ground-fault
circuit-interrupter - Also called a GFI or GFCI- 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
(usually 1/40th of a second and 5/1000th of an
ampere).
GUNITE
A
mixture of cement and sand sprayed onto contoured and
supported surfaces to build a pool. Gunite is mixed and
pumped to the site dry, and water is added at the point
of application. Plaster is usually applied over the
gunite.
GUTTER
An
overflow trough at the edge of the pool through which
floating debris, oil and other "lighter-than-wate" things
flow. Pools with gutters usually do not have
skimmers.
HALOGENS
The
chemical elements either individually or collectively
that constitute Group VIIB of the Periodic Table of
Elements: fluorine, chlorine, bromine, iodine and
astatine. Of these, only chlorine and bromine are used as
disinfectants and sanitizers in pools and
spas.
HAND
RAIL
A
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.
HAND
SKIMMER
A
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.
HARDNESS
The
amount of calcium and magnesium dissolved in the water.
"Water" or "total" hardness refers to the total magnesium
and calcium dissolved in the water. Calcium hardness
refers to just the calcium. Measured by a test kit and
expressed as ppm. The proper range is 200 to 400
ppm.
HEAT
EXCHANGER
A
device located inside the heater providing for the
transfer of heat from the heat source to the water. This
is usually a seriew of metallic tubes with fins located
just above the flames.
HEATER
A
fossil-fueled, electric or solar device used to heat the
water of a pool, spa or hot tub.
HERBICIDE
A
chemical compound used to kill or control plant growth or
algae. Simazine is a common pool
herbicide.
HORSEPOWER
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.
HOT
TUB
A
spa constructed of wood with the sides and bottom formed
separately and joined together by hoops, bands or
rods.
HYDROCHLORIC
ACID
Also
called muriatic acid - A very strong acid used in pools
to lower the pH and total alkalinity. It can also be used
for various cleaning needs. Used in "acid washing" a
pool. Use extreme care in handling.
HYDROGEN
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.
HYDROGEN
ION
The
positively charged nucleus of hydrogen atom. The relative
degree of acid or base of a solution (called pH) is a
measure of hydrogen ions.
HYDROGEN
PEROXIDE
An
unstable, colorless, heavy liquid used as a bleach in
industry and as an antiseptic in households. It is used
as an oxidizing agent in pools and spas. May also be used
to de-chlorinate pool or spa water.
HYDROJET
A
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.
HYPOBROMOUS
ACID
The
most powerful disinfecting form of bromine in water.
Sometimes called the killing form of
bromine.
HYPOCHLORITE
The
name given to a family of chlorine containing compounds,
including calcium hypochlorite, sodium hypochlorite and
lithium hypochlorite, that are used as disinfectants and
sanitizers in pool and spa water.
HYPOCHLOROUS
ACID
The
most powerful disinfecting form of chlorine in water.
Sometimes called the killing form of
chlorine.
IMPELLER
The
rotating member of a pump. The part of the pump that
moves the water.
INFLUENT
The
water entering the pump, the filter or other equipment of
space. Water going into the pump is called in influent,
while water leaving the pump is called the
effluent.
INLET
A
fitting in the pool or spa on the water return line from
the equipment that water returns to the pool. Usually the
last thing on the return line.
IONIZER
A
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. The copper is an
algaecide, while the silver is a bactericide. Does not
remove swimmer waste.
IRON
Iron
in water causes the water to be brown- or green-colored.
Can be controlled by the addition of a sequestering agent
or a chelating agent. Water can be tested with an iron
test kit.
ISOCYANURATES
Also
called stabilized chlorine - A family of chlorine pool
sanitizers that contain conditioner (cyanuric acid or
isocyanuric 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 broadcasting
into the pool or spa. Tablet or stick form is trichlor
(which is usually used in a chlorine feeder - either the
floating type or the in-line erosion type) used for
regular chlorination only.
JACUZZI
A
brand name of a spa or whirlpool. The term has been used
so frequently to describe a generic (just like Kleenex,
Xerox or Scotch Tape) spa, that Jacuzzi has come to mean
spa.
LADDER
A
structure for climbing up or down; consists of two
parallel sides joined by a series of crosspieces that
serve as footrests. It is used for getting in and out of
the pool. A double-access ladder straddles the pool wall
of an above-ground pool. An in-pool ladder is located in
the pool only.
LEAF
BAGGER
A
device that attaches to a telepole and a garden hose.
Pressure from the garden hose creates a venturi by which
leaves and large debris are drawn into a large mesh
bag.
LIGHT
NICHE The area in a pool or spa that houses the
underwater light fixture.
LINER
Also
called vinyl liner - The vinyl membrane that acts as the
container to hold or contain the water.
LIQUID
ACID
31.45%
hydrochloric acid) - also called muriatic acid - It is
used for lowering pH, total alkalinity and for various
cleaning needs. It is also used for acid
washing.
LIQUID
CHLORINE
A
sodium hypochlorite solution. Usually provides 10 to 12%
available chlorine; has a pH of 13 and requires that
small amounts of acid be added to the pool to neutralize
the high pH. Good for regular chlorination and
superchlorination.
LITHIUM
HYPOCHLORITE
A
dry, granular chlorinating compound with an available
chlorine content of 35%. It is fast-dissolving and can be
used to superchlorinate vinyl-liner pools, painted pools
or fiberglass pools as well as spas and hot
tubs.
MAGNESIUM
HARDNESS
A
measure of the amount of magnesium dis- solved in the
water. It is part of total or water hardness. It also
causes scale if levels are too high.
MAIN
DRAIN
This
term usually refers to a plumbing fitting installed on
the suction side of the pump in pools, spas and hot tubs.
Sometimes called the drain and 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.
MAKE-UP
WATER
This
is sometimes called "tap" or "refill" water. It is the
water used to replace water lost to evaporation,
splash-out, leaks or swimmer drag-out in the
pool.
MANIFOLD
The
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 septa back into one common
pipe.
MARCITE
Originally
a brand name for a white plaster finish coat from 1/8th
to 1/2 inch thick applied over the gunite or
shotcrete.
MICRON
A
unit of length equal to 1 millionth of a meter - it is
.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 D.E. (diatomaceous earth) filters have
openings of 1 to 5 microns. Humans, without
magnification, can see objects 35 microns or larger. A
granule of table salt is between 90 to 110
microns.
MINERAL
Any
substance that is neither animal or vegetable. It is any
class of substances occurring in nature, usually
comprising 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 in
contact with,the minerals dissolved in the water may be
just a few or they may be many. Water handness is mostly
comprised of these minerals.
MULTIPORT
VALVE
Also
called a rotary-type backwash valve - This valve replaces
as many as 6 regular gate valves. 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.
MURIATIC
ACID
(31.45%
hydrochloric acid) - Also called liquid acid - An acid
used to reduce the pH and alkalinity levels in pool
water. It is also used in acid washing, a process that
removes stains and scale from pool
plaster.
NEUTRALIZER
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
pool water tests. 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.
NITROGEN
A
gas that causes algae to bloom and disables chlorine. It
is brought into the water each time it rains. Maintaining
proper chlorine levels will prevent nitrogen from
becoming a problem. Superchlorination will remove
nitrogen and its related compounds.
NON-CHLORINE
SHOCK
A
term given to a class of chemical compounds that are 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.
NORYL
The
brand name for a thermoplastic resin used in the
manufacture of certain pump components and various other
pool equipment fittings.
ORGANIC
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. See organic
waste.
ORGANIC
WASTE
Also
called swimmer or bather waste - All of the soap,
deodorant, suntan lotion, kipstick, makeup, cologne, body
oils, sweat, spit, urine, etc., brought into the water.
They also form chloamines, which are foul-smelling and
body irritants. Requires large amounts of chlorine or
non-chlorine shock to destroy.
ORP
An
abbreviation for exidation reduction reduction potential.
It is a measurement of a body of water's ability to
exidize contaminants. Measured with an electrode and an
electronic meter. It is 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).
OTO
Abbreviation
for orthotolidine. A chemical reagent used to test the
total chlorine level in pool and spa water. It does not
measure free available chlorine. See DPD.
OVER-ACID
An
incorrect term used to describe water that is acidic or
water that has a pH lower than 7.2.
OVERDRAIN
Also
called a diffuser or distributor - An internal sand
filter device that evenly distributes influent pool water
over the sand filter bed.
OXIDATION
To
rid the water of ammonia, nitrogen compounds and swimmer
waste (organic 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.
OXIDIZER
A
non-chlorine shocking compound that removes or destroys
built-up contaminants and chloramines in pool water
without raising chlorine levels as required when
"superchlorinating."
OZONE
A
gaseous molecule comprised of 3 atoms of oxygen. It is
generated by the exposure of air or oxygen to either ultraviolet rays or electricity and is used for
oxidization of water contaminants.
PATHOGENIC
ORGANISM
An
organism that causes disease.
PETCOCK
A
small, manually operated faucet or valve for draining off
liquids or releasing air pressure. The air-relief valve
on a filter is an example.
PHENOL
RED
A
chemical reagent dye used to test for pH. It can measure
pH from 6.8 to 8.4.
PLASTER
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 or
spa.
POLYMER
A
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.
POTASSIUM
PEROXYMON
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 destroy ammonia, nitrogen and swimmer waste.
It has a low pH, and it does not increase chlorine or
bromine levels the way that superchlorination does, so
water may be entered in 15 minutes after addition. It
will also reactivate bromine to its killing form,
hypobromous acid.
PRECIPITATE
A
substance separating, in solid particles, from a liquid
as a result of a chemical or physical change. It also
means to form a precipitate.
PRECOAT
Depositing
diatomaceous earth (D.E.) onto the filter grids or
elements.
PRESSURE
GAUGE
A
gauge with an analog dial indicating the pounds per
square inch (psi) of pressure that has built up within a
closed container, such as a filter.
PUMP
A
mechanical device, usually powered by an electric motor,
which causes hydraulic flow and pressure for the purpose
of filtration, heating and circulation of pool and spa
water. Typically, a centrifugal pump is used for pools,
spas and hot tubs.
PUMP
CAPACITY
The
volume of liquid a pump is capable of moving during a
specified period of time. This is usually gallons per
minute (gpm).
PUMP
CURVE
Also
called a pump performance curve - A graph that represents
a pump's water flow capacity at any given
resistance.
PUMP
STRAINER BASKET.
Pump
Strainer Basket - A device placed on the suction side of
the pump, which contains a removable strainer basket
designed to trap debris in the water flow without causing
much flow restriction. Sometimes called a "hair-and-lint
trap."
QUATS
Quaternary
Ammonium Compounds - Also called Quats - The chemical
compounds of ammonia used as algaecides and
algaestats.
RATE
OF FLOW
The
quantity of water flowing past a designated point within
a specified time, such as the number of gallons flowing
past a point in 1 minute - abbreviated as
gpm.
REAGENTS
The
chemical agents, dyes, indicators or titrants used in
testing various aspects of water quality.
RESIDUAL
BROMINE
The
amount of measurable bromine remaining after treating the
water with bromine. The amount of bromine left in the
pool or spa water after the bromine demand has been
satisfied.
RESIDUAL
CHLORINE
The
amount of measurable chlorine remaining after treating
the water with chlorine. The amount of chlorine left in
the pool or spa water after the chlorine demand has been
satisfied.
SAND
This
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 (millimeters).
SAND
FILTER
A
filter using sand or sand and gravel as the filter
medium.
SANITIZE
To
render sanitary: to kill all living things, including
bacteria and algae. Similar to sterilize.
SCALE
The
precipitate that forms on surfaces in contact with water
when the calcium hardness, pH or total alkalinity levels
are too high. Results from chemically unbalanced pool and
spa water. Scale may appear as grey, white or dark
streaks on the plaster, fiberglass or vinyl. It may also
appear as a hard crust around the tile.
SCUM
The
extraneous or foreign matter which rises to the surface
of the water and forms a layer or a film there. It can
also be a residue deposited on the tile or walls of the
pool or spa. Sources of scum are soap, oil, deodorant,
hair spray, suntan lotions and others.
SEDIMENT
The
solid material settled out from the
water.
SEPTUM
That
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.
SEQUESTERING
AGENT
Also
called 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.
SHOCK
TREAT
The
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.
SHOTCRETE
A
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.
SILT
Soil
particles having diameters between 0.004 and 0.062 mm
(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.
SIMAZINE
A
chemical substance used in swimming pools and spas as an
herbicide or algaecide. Mainly used for killing black
algae.
SKIMMER
A
device installed through the wall of a pool or spa that
is connected to the suction line of the pump that draws
water and floating debris in the water flow from the
surface without causing much flow
restriction.
SKIMMER
BASKET
A
removable, slotted basket or strainer placed in the
skimmer on the suction side of the pump, which is
designed to trap floating debris in the water flow from
the surface without causing much flow
restriction.
SKIMMER
WEIR
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 water flows on
its way to the skimmer. The weir also prevents debris
from floating back into the pool when the pump shuts
off.
SLURRY
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.
SODA
ASH
(Sodium
Carbonate) - A chemical used to raise pH in pool and spa
water..
SODIUM
BICARBONATE
A
chemical used to raise total alkalinity in pool and spa
water with only a slight affect on the
pH.
SODIUM
BISULFATE
(dry
acid) - A chemical used to lower the pH and total
alkalinity. 2 1/2 lbs. of dry acid are equal to 1 quart
of muriatic acid.
SODIUM
BROMIDE
A
salt of bromine. It is used to establish a bromide "bank"
in pool and spa water prior to beginning the use of
bromine tablets.
SODIUM
CARBONATE
(soda
ash) - A chemical used to raise the pH in pool and spa
water.
SODIUM
DI-CHLOR
A
fast-dissolving, granular, stabilized organic chlorine
compound providing either 56% or 63% available chlorine.
Used for regular as well as superchlorination. Contains
an ingredient (cyanuric acid or stabilizer) that prevents
the chlorine from being destroyed by the ultraviolet (UV)
rays of the sun. Recommended for use in vinyl-liner,
painted or fiberglass pools and acrylic or fiberglass
spas.
SODIUM
HYPOCHLORITE
Liquid
chlorine. Usually provides 10% to 12% available chlorine;
has a pH of 13 and requires that small amounts of acid be
added to the pool to neutralize the high pH. Good for
regular chlorination and superchlorination. Not
recommended for spas. 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
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 destroy ammonia,
nitrogen and swimmer waster. Does not increase chlorine
or bromine levels the way that superchlorination does, so
water may be entered in 15 minutes after addition. It
will not reactivate bromine.
SODIUM
SESQUICARBONATE
A
chemical mixture of equal parts of soda ash and sodium
bicarbonate used to increase pH and total alkalinity in
pool and spa water. It has a pH of 10.1.
SODIUM
SULFITE
A
chemical used to neutralize or de-chlorinate pool and spa
water.
SODIUM
THIOSULFATE
A
chemical used to neutralize or de-chlorinate pool and spa
water.
SODIUM
TRICHLOR
(Sodium
Trichlorotriazinetrione) - Potent - 90%+ available
chlorine - (stabilized), found in tablet form, and
dispensed in feeders, both floating and automatic.
Very acidic.
SOFT
WATER
Water
that has a very low calcium and magnesium content (water
hardness) - usually means less than 100 ppm or 6 grains.
Also water that has gone through a water softerer. 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 to 200 ppm using calcium
chloride.
SOLAR
COVER
A
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 wind-borne debris from entering
the water.
SOLAR
HEATING SYSTEM
Typically,
this consists of panels or coils of plastic or metal
through which water passes to increase the temperature
from the sun's radiant heat.
SOURCE
WATER
Also
called "tap" water - It is the water used to fill or
refill the pool or spa.
SPRING
BOARD
Also
called "diving" board - A 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.
STABILIZED
CHLORINE
A
family of chlorine pool sanitizers that contain
conditioner (cyanuric acid or isocyanuric acid) to
protect the chlorine from the degrading UV rays in
sunlight. 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 broadcasting into the pool or
spa. Tablet or stick form is trichlor (which is usually
used in a chlorine feeder - either the floating type or
in-line erosion type) used for regular chlorination
only.
STAIN
A
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 & manganese. They may appear as
green, gray, brown or black. They may even 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 & bottom. The
metals get in the water because the pH was too low or
someone has added a low pH chemical directly into the
circulation system. The low pH chemical dissolves a small
amount of metal from the equipment. The metals begin to
come out of solutions & deposit or stain the walls
& bottom. Stains are sometimes confused with
scale.
STAIN
INHIBITOR
Also
called 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.
SUPERCHLORINATION
The
practice of adding an extra large dose (5 to 10 ppm) of
chlorine to the water to destroy ammonia, nitrogen and
swimmer waste, which can build up in the water. This
level of chlorine is required to destroy all of the
combined chlorine in the water, which is called
breakpoint chlorination.
SURFACTANT
A
soluble chemical compound that reduces the surface
tension between two liquids. It is used in many
detergents and soapy cleaning compounds.
SUSPENDED
SOLIDS
Insoluble
solid particles that either float on the surface of or
are in suspension in the water, causing turbidity. 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.
TEE
A
plumbing fitting in the shape of a "T" used to connect
pipes.
TELEPOLE
A
long-handled aluminum pole, which extends in length,
which various pool cleaning tools, such as brushes or
vacuums, may be attached.
TEST
KIT
An
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: pH,
total alkalinity, free available chlorine, water
hardness, cyanuric acid, iron and copper.
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. The
strips are usually dipped in the water, and the resulting
colors of the pads are compared to a standard set of
colors to determine concentration.
TIME
CLOCK
A
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.
TOTAL
ALKALINITY
The
total amount of alkaline materials present in the water.
Also called the buffering capacity of the water. It is
the water's resistance to change in pH. Low total
alkalinity causes metal corrosion, plaster etching and
eye irritation. High total alkalinity causes scale
formation, poor chlorine efficiency and eye
irritation.
TOTAL
CHLORINE
The
total amount of chlorine in the water. It includes both
free available and combined chlorine.
TOTAL
DISSOLVED SOLIDS
Total
Dissolved Solids - Also called TDS - A measure of the
total amount of dissolved material in the water. It is
comprised of the spent or carrier chemicals added every
time chemicals are added, as well as the hardness,
alkalinity, chlorides, chlorides, sodium, magnesium,
calcium, etc. 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.
TRICHLOR
A
slow-dissolving, tableted or granular, stabilized organic
chlorine compound provid- ing 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 (cyanuric acid or
stabilizer) that prevents the chlorine from being
destroyed by the ultraviolet (UV) rays of the sun.
Tri-chlor has a 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.
TURBIDITY
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 an organic polymer or alum, will
coagulate the particles and make the filter more
efficient.
TURNOVER
Also
called turnover rate - The period of time (usually in
hours) required to circulate a volume of water equal to
the volume of water contained in the pool or spa. Pool
capacity in gallons, divided by pump flow rate in gallons
per minute (gpm), divided by 60 minutes in 1 hours, will
give hours for 1 turnover.
UNDERDRAIN
Also
call filter laterals or lower collection system -
Slotted, finger-like tubes that are attached to a sand
filter manifold. The slots are on the bottom side to
prevent the sand from passing through. Water comes into
the filter tank, through the sand, into the underdrain,
and then back to the pool.
UNDERWATER
LIGHT
A
fixture designed to illuminate a pool or spa from beneath
the water's surface.
VACUUM
This
term can be used to define any number of devices that use
suction to collect dirt from the bottom and sides of a
pool or spa. Most common 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 by a person, and debris is collected
in the filter.
VENTURI
A
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 hydro-therapy
jet draws air in and mixes it with the water using this
principle.
VINYL
LINER
The
vinyl membrane that acts as the container to hold or
contain the water.
WATER
CLARIFIER
Also
called coagulant or flocculant - A 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; inorganic salts of
aluminum (alum) and other metals or water-soluble organic
polyelectrolytes.
WEIR
Also
called skimmer weir - Part of a skimmer that adjust
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 water flows on its way to the skimmer.
The weir also prevents debris from floating back into the
pool after the pump shuts off.
pH
Potential
Hydrogen - Indicates the level of acidity or alkalinity
of water on a scale ranging from 0-15. A low pH causes
etched plaster, metal corrosion and eye irritation. A
high pH causes scale formation, chlorine inefficiency and
eye irritation. The ideal range for pH in swimming pools
is 7.4 to 7.6.
ppm
An
abbreviation for parts per million. It is a
weight-to-weight expression. It means 1 part in 1 million
parts, such as 1 lb. of chlorine in 1 million lbs. of
water. Many of the common pool water tests, as well as
acceptable ranges, are stated as ppm. For example, free
available chlorine should be kept between 1.0 and 3.0
ppm; total alkalinity should be between 80 and 120 ppm;
and and water hardness should be between 200 and 400
ppm.
psi
An
abbreviation for pounds per square inch.
-
Home
| Catalog
| Order
| Technical
| Price
Quote
| UPS
Tracking
| Links
| Contact
Us