ACID: A chemical substance containing
hydrogen with the ability to neutralize
alkaline materials. Acid is used to
lower the pH or total alkalinity of
swimming pool water. Most common are
hydrochloric acid (muriatic) and dry
acid (sodium bisulfate).
ACID DEMAND: The amount of acid required
to bring high pH or total alkalinity
down to their proper levels. Determined
by an acid demand test.
ACID DEMAND TEST: A reagent test usually
used in conjunction with a pH test to
determine the amount of acid needed to
lower pH or total alkalinity.
ACID RAIN: Precipitation having a low pH
value caused by air polluted with sulfur
dioxide, carbon dioxide or nitrous
oxide.
AIR BLEEDER ASSEMBLY: See Air-Relief
Valve
AIR-RELIEF VALVE: A manually operated
valve located on the top of a filter
tank for relieving the pressure inside
the filter or for removing the air
trapped inside the filter (bleeding the
filter). Sometimes called a
Pressure-Relief Valve.
ALGAE: Microscopic plant-like organisms
that contain chlorophyll. Algae are
nourished by carbon dioxide (CO2) and
use sunlight to carry out
photosynthesis. They find their way into
the pool by rain or wind and grow in
colonies, resulting in algae blooms.
Algae do not cause disease, but provide
an ideal substrate for bacteria to
thrive in. There are over 21,000 known
species of algae. The most common pool
types are black algae, blue-green algae,
green algae and mustard algae. Pink
algae or red algae-like organisms can be
found, but are in fact bacteria.
Maintaining proper sanitizer levels,
shock treatments and super chlorination
will help to prevent or destroy algae.
ALGAECIDE: Meaning to kill algae.
Algaecides perform best as a backup to a
routine sanitation program. They also
help to kill airborne spores as they
blow into the pool. A variety of algae
treatment products are available
including copper and silver compounds,
quat compounds, chlorine enhancers and
herbicides. Algaecides are often
formulated for a specific type of algae
(green algae, mustard algae, black
algae) with black algae being the
hardest to treat.
ALGAESTAT: An algaecide kills algae,
while an algaestat retards and prevents
its development and growth.
ALGEA: See Algae
ALGICIDE: See Algaecide
ALKALI: Also called a Base. An alkali is
the opposite of acid and is used to
increase the pH or total alkalinity of
swimming pool water. Most common are
sodium carbonate or sodium hydroxide to
increase pH, and sodium bicarbonate to
increase total alkalinity.
ALKALINITY: Also called Total
Alkalinity. A measure of the
pH-buffering capacity of water or the
water's resistance to change in pH. It
is composed of the hydroxides,
carbonates and bicarbonates in the
water. When we measure the total
alkalinity, we usually only measure the
carbonate alkalinity level.
ALUMINUM SULFATE: Also known as Alum.
This product is used as a flocculant
which attracts suspended particles in
the water to each other. Alum sinks
everything to the bottom, which can then
vacuumed to waste. A small amount of
alum can also be used as a sand filter
additive.
AMMONIA: (NH3) It is a
nitrogen-containing compound introduced
into the water by swimmers as waste
(perspiration or urine) or by other
means. It quickly combines with chlorine
to form bad-smelling chloramines, which
are harmful to our health.
ANTI-FOAM: A chemical added to the water
to reduce the foam. These products do
not remove the source of the foaming.
Shocking and super chlorination may help
prevent foaming. Careful use of cheaper
algaecides/ algaestats can prevent
foaming.
AUTOMATIC POOL CLEANER: A pool
maintenance system that will brush or
vacuum dirt and debris from the interior
of the pool automatically. Some cleaners
work on low-voltage electricity, others
on the pump's suction line. The pool
cleaner may be programmable, automatic
or may move randomly around the pool.
Some cleaners can climb the walls of the
pool, while others only clean the floor.
AVAILABLE CHLORINE CONTENT: A term used
to compare the amount of oxidizing power
that chorine-containing products have
when compared to gas chlorine(Cl2). It
permits easy comparison of relative
values of chlorine compounds.
AVAILABLE CHLORINE: The amount of free
chlorine that is available to sanitize
or disinfect the water. It is also
called Residual Chlorine and Free
Available Chlorine.
BACKFLOW: The back-pressure of water in
a pipe in the opposite direction to
normal flow.
BACKWASH: Thoroughly cleaning a sand
filter by reversing the flow of water
through it so that the dirt and rinse
water go to waste.
BACTERIA: Unicellular microorganisms of
various forms. Some are pathogens, which
can cause infectious diseases. Bacteria
are controlled by chlorine, bromine or
other sanitizers or disinfectants.
BACTERICIDE: Meaning to kill bacteria.
It is a chemical (e.g. chlorine) or an
element (e.g. silver) that kills
bacteria.
BAKING SODA: Chemically, Sodium
Bicarbonate. It is white powder used to
raise the total alkalinity of pool water
without having much affect on pH. It
will only increase pH up to 8.5,
regardless of the quantity used. Care
should be taken, however, to avoid
adding large quantities at one time.
BALANCED WATER: Balanced water is the
result when all of your chemical
parameters are within the tolerance
limits. The most important parameters of
water balance are pH, Total Alkalinity,
Calcium Hardness and Temperature, as
measured using the Langelier Saturation
Index .
BASE: Chemicals of alkaline nature which
will counteract the pH of an acid.
Common bases used around the pool
include Soda Ash, Sodium Bicarbonate and
Sodium Carbonate. A base is the opposite
of an acid. See Alkali
BASE DEMAND: A titration test used to
determine the amount of a base (alkali)
required to increase the pH to the
correct level.
BCDMH: Chemically, "bromochlorodimethylhydantoin",
it is a bromine sanitizer. When BCDMH
dissolves in water it produces
Hypobromous Acid and Hypochlorous Acid.
BICARB: See Sodium Bicarbonate..
BLEACH: This term usually refers to
liquid chlorine. It is the same chemical
used in the home, but pool chlorine
(sodium hypochlorite) has 12% - 15%
available chlorine while laundry bleach
only has about 5% available chlorine.
BLEACHING OUT: At above 10ppm free
available chlorine in a pool, a DPD test
kit often indicates zero chlorine
because the reagent is being destroyed.
If you observe an initial pink color
which then rapidly fades, you probably
have far too much residual chlorine in
the water.
BIGUANIDES: The name for a certain class
of sanitizers using the polymer PHMB,
the only non-halogen sanitizer available
for pool use. Soft Swim and Baquacil are
manufacturers of this sanitizer.
Biguanides are NOT compatible with the
Pool Wizard.
BLUE FINGERNAILS: A condition caused by
too much free copper in the pool water.
Can result from cheaper copper-based
algaecides, overuse of these algaecides
or corrosive water. See also Green Hair.
BOOSTER PUMP: In addition to the filter
pump, a booster pump may be necessary to
power some automatic pool cleaners.
BREAKPOINT CHLORINATION: When you shock
treat your pool, the goal is to reach a
high enough level of free chlorine to
break apart all molecular bonds;
specifically the combined chlorine
molecules, ammonia or nitrogen compounds
and to completely oxidize all organic
matter. Adding enough chlorine to
achieve this is breakpoint chlorination.
Chlorine added after that point will be
free available chlorine.
BROMAMINES: By-products formed when
bromine reacts with swimmer waste
(perspiration or urine), ammonia or
nitrogen. Unlike chloramines, which are
strong smelling and have very low
sanitizing properties, bromamines are
active disinfectants and do not smell,
although high levels are harmful to your
health.
BROMIDE: A common term for a bromide
salt which, when added to water becomes
hypobromous acid, the active form of
bromine. It is used as a disinfectant in
swimming pools.
BROMINATOR: A mechanical or electrical
device for dispensing bromine at a
controlled rate. It is most commonly a
canister or floater filled with bromine
tablets.
BROMINE: A member of the halogen family
commonly used as a sanitizer or
disinfectant to destroy bacteria and
algae in swimming pools. It is resistant
to heat and rapid pH fluctuations.
Available as a tablet or as sodium
bromide, a granular salt.
BUFFER: A chemical which results in
resistance to changes in pH. A base such
as Sodium Bicarbonate, when added to
your pool will increase total
alkalinity. This in turn increases the
buffering capacity of the pool; i.e.
your pool's resistance to pH change.
BUFFERING CAPACITY: The ability of the
pool to resist changes in pH. The
buffering capacity is determined by the
total alkalinity. If your pH bounces, or
resumes previous levels soon after
adjustment, the buffering capacity is
too low. If your pH rises rapidly, even
after the addition of large amounts of
acid, the buffering capacity is too
high. If the pool has an unstable pH,
the total alkalinity should be tested
and adjusted.
BYPASS: An arrangement of pipes, gates
and valves by which the flow of water
may be passed around the filter rather
than through it, and usually refers to
circulating the water without
filtration.
CALCIUM CARBONATE: Crystalline compounds
formed on swimming pool surfaces when
the calcium hardness, pH or total
alkalinity levels are too high. Once
formed, the crystals adhere to the
plumbing and pool surfaces. These
crystals are also known as scale.
CALCIUM CHLORIDE: A soluble white salt
used to raise the calcium hardness or
total hardness level of pool water.
CALCIUM HARDNESS: The calcium content of
the water. If the calcium hardness level
is too low, the water may be corrosive.
If the calcium hardness level is too
high, the water may have a tendency to
form scale.
CALCIUM HYPOCHLORITE: A compound of
chlorine and calcium used as a
disinfectant, sanitizer, bactericide,
algaecide and oxidizer in swimming pool
water. It is available as a white
granular powder which usually contains
65% - 70% available chlorine and has a
pH of 11.8 . It is also used as a
disinfectant in drinking water.
CARBON DIOXIDE: A gas, which when
present in the water, provides necessary
nutrients for the algae to
photosynthesise and reproduce in the
presence of sunlight. Also used to lower
pH in large pools.
CARTRIDGE: A disposable porous element
made of paper or polyester which is used
as the filter medium in cartridge
filters.
CARTRIDGE FILTER: A water filter that
uses a replaceable porous element made
of paper or polyester.
CHECK VALVE: A mechanical device in a
pipe that permits the flow of water in
one direction only. Also called a
one-way valve or a non-return valve.
CHELATOR: A chelating agent is a water
soluble molecule that can bond tightly
with metal ions, keeping them from
coming out of suspension and depositing
their stains and scale onto pool
surfaces and equipment. Similar to
sequestering agents.
CHELATED COPPER: Copper algaecides that
contain a special ingredient to prevent
the copper from staining the pool
surfaces or producing colored water.
CHEMICAL FEEDER: A device that dispenses
chemicals into the pool water at a
predetermined rate. Some provide
chlorine or bromine while others add
pH-adjusting chemicals.
CHLORAMINES: Undesirable smelly
compounds formed when insufficient
levels of free available chlorine react
with ammonia and other nitrogen
containing compounds (swimmer waste,
sweat, urine, ...). Chloramines are a
threat to human health and are very poor
sanitizers. Chloramines can be destroyed
by shock treatment or superchlorination.
CHLORINATOR: A mechanical or electrical
device for adding chlorine to a pool at
a controlled rate. Most often a floater
filled with tablets of chlorine or an
in-line feeder.
CHLORINE: A member of the halogen family
of sanitizers. Its use in swimming pools
is in the form of a gas, as a liquid, in
granular or tablet forms. When added to
water it acts as an oxidizer, sanitizer,
disinfectant and biocidal agent.
CHLORINE, combined: The measure of
chlorine which has attached itself to
other molecules or organisms, typically
ammonia or nitrogen compounds. Most of
these compounds are present as unwanted
chloramines.
CHLORINE, free available: Free available
chlorine is active chlorine and is not
combined with any other molecule. A
portion of the free available chlorine
is present as hypochlorous acid, which
reacts to destroy organic material in
the pool water.
CHLORINE, total: The sum of combined and
free available chlorine levels. With a
DPD test kit, DPD1 determines free
available chlorine and DPD3 shows total
chlorine. The difference, if any, is the
level of combined chlorine.
CHLORINE DEMAND: The amount of chlorine
necessary to oxidize all organic matter
(bacteria, algae, chloramines, ammonia
and nitrogen compounds, . . .) in the
pool water.
CHLORINE ENHANCER: A chemical compound
used in conjunction with chlorine, that
makes the chlorine perform better as an
algaecide.
CHLORINE GENERATOR: An electrical device
that generates chlorine from a salt
solution. The salt solution may be in a
separate tank or may be in the pool
itself.
CHLORINE LOCK: If the level of cyanuric
acid (stabliser) in the water is much
over 80ppm, the chlorine becomes trapped
and is unable to oxidize effectively.
Despite being able to measure normal
chlorine levels, the Redox potential is
very low, indicating a lack of oxidizer.
The only way to fix this is to drain
some of the water and refill the pool.
Care should be taken when using
stabilized chlorine products (dichlor or
trichlor) to avoid the level of cyanuric
acid increasing too much.
CHLORINE NEUTRALIZER: A chemical used to
deactivate or destroy chlorine. It is
used in better test kits to prevent the
bleaching effect of the chlorine and
consequently to increase the accuracy of
the tests.
CHLORINE RESIDUAL: Also called Free
Available Chlorine. The amount of
chlorine left in the pool water after
the chlorine demand has been satisfied.
CLARIFIER: Also called a coagulant or
flocculant. A chemical compound used to
coagulate, clump or precipitate
suspended microparticles so they can be
removed by vacuuming or filtration.
There are two main types; inorganic
salts of aluminum (alum), or organic
polyelectrolytes.
CLARITY: The degree or measure of the
transparency of water.
CLINOPTILOLITE: The zeolite that is used
as an alternative to quartz as the
filter medium in sand filters.
COAGULANT: An organic polyelectrolyte
that helps the filter by clumping minute
particles together so they can be
trapped by the filter.
COMBINED CHLORINE: See Chlorine,
combined.
COMPENSATION TANK: The tank into which
the water from the gutters or skimmer
gutters flows. The tank serves to ensure
that the pool has enough water to
overflow regardless of the number of
swimmers and independent of evaporation
and splash-out losses.
CONDITIONER: Chemically known as
cyanuric acid and also called
stabilizer. It protects chlorine in the
water against the effects of the sun's
UV rays.
CONTAMINANTS: The general name for any
microparticle or organism which reduces
water clarity, quality or presents
health hazards. Filtering, oxidising and
sanitising are necessary to destroy the
contaminants.
COPPER: An effective algaestat and
algaecide and is one of nature's natural
elements. It may also be used in the
equipment and plumbing in swimming
pools. High levels of copper may stain
hair, fingernails or pool surfaces and
can also result in green, brown or blue
water.
COPPER ALGAECIDE: A chemical compound
that contains the element copper. Most
copper algaecides contain ingredients
that prevent the copper from staining
but do not affect copper's ability to
kill algae. These are known as chelated
copper algaecides.
COPPER SULFATE: Copper sulfate was one
of the original copper algaecides. It is
similar to aluminum sulfate in that it
provides a flocculant function in water.
It can be used in ponds but may harm
some aquatic creatures in high
concentrations. The amount of copper
required to be effective would stain
swimming pools.
CORROSION: The effects of an acidic pool
environment; one in which the pH and/or
alkalinity are very low. Corrosion in
the form of etching, pitting or erosion
of pool equipment and surfaces is the
result. May also be caused by misuse of
acid or by soft water.
COVER, hard-top: A cover used on pools
that rests on the edge of the pool deck
and does not come into contact with the
water.
COVER, solar: A floating cover that
increases the water temperature by
absorption and transmission of solar
radiation and reduces evaporation and
pollution from the environment.
COVER, winter: A cover that is secured
around the edges of a pool when the pool
is closed for the season.
CYANURIC ACID: Also called conditioner
and stabilizer. A granular chemical
added to the pool water which provides a
shield to chlorine for protection from
the sun's UV radiation. It is also found
in dichlor/ trichlor products.
D.E. FILTER: See Diatomaceous Earth
Filter
DEFOAMER: Also called anti-foam. A
chemical added to the water to destroy
the foam. These products do not remove
the source of the foaming. Shocking and
super chlorination may help prevent
foaming. Controlled use of certain of
the cheaper algaecides can prevent their
resulting in foaming.
DIATOMACEOUS EARTH: Also called D.E. A
white powder composed of fossilized
skeletons of unicellular organisms
called diatoms. The skeletons are porous
and have microscopic spaces. The powder
is added through the skimmer with the
pump on and deposits itself on a grid.
The powder then becomes the filter
medium.
DIATOMACEOUS EARTH FILTER: A filter
designed to use diatomaceous earth (D.E.)
as the filter medium. The D.E. is added
through the skimmer with the pump on,
which deposits the D.E. on a grid. The
D.E. becomes the filter medium.
DICHLOR: The common name for Sodium
Dichloro Isocyanuric Acid. A quick
dissolving chlorine compound made up of
chlorine and cyanuric acid (stabilizer)
and has a pH of 6.9 . Shock treatment
with dichlor is not recommended as it
may result in overstabilisation and
chlorine lock. If dichlor is used, a
monthly check of the cyanuric acid level
is recommended, to prevent
overstabilisation and chlorine lock.
DISINFECT: To kill all pathogenic
(disease-causing) organisms.
DISINFECTANT: Chemicals, elements or
processes which destroy vegetative forms
of microorganisms and other
contaminants. Examples are chlorine,
bromine, ionisers, ozonators and copper
& silver algaecides.
DISSOLVED SOLIDS: See Total Dissolved
Solids
DPD: Chemically, NN Diethyl-p-Phenylene
Diamine Sulfate. An indicator reagent
used to measure free available chlorine
(DPD1) and total chlorine (DPD3),
bromine, ozone and other oxidizers in
water. Far superior to OTO.
DRAIN: A plumbing fitting installed on
the suction side of the pump in pools.
Also called the main drain, it is
located in the deepest part of the pool.
Main drains are connected to the pump
for circulation, filtration and emptying
of the pool.
DRY ACID: Chemically, sodium bisulfate.
A dry white crystal that produces acid
when added to water. It is used to lower
pH and total alkalinity and is safer to
handle than liquid acid (hydrochloric
acid/ muriatic acid).
EPA: Abbreviation for the U.S.
Environmental Protection Agency.
EFFICACY: The power to produce an
effect. Chlorine's efficacy is affected
by many factors, including the sun,
temperature, water balance and the
water's chlorine demand.
ENZYMES: Used in commercial swimming
pool formulations to break down and
destroy oils in the swimming pool.
FIBREGLASS: Fine threads of glass which
are available in the form of a rope or a
mat. When polyester resins, catalysts
and hardeners are applied to fiberglass,
it can be formed or molded into pools,
water tanks, boats and many other items.
FILL WATER: The water used in filling or
topping up the swimming pool.
FILTER: A device that removes
undissolved or suspended particles from
water by the flow of the water through a
porous substance (a filter medium or
element). The three main types of
filters used in pools are sand filters,
cartridge filters and D.E. (diatomaceous
earth) filters.
FILTER AID: A chemical compound added to
the water, filter or skimmer that allows
the existing filter to become more
efficient. They are generally
flocculants, coagulants and diatomaceous
earth.
FILTER AREA: The total surface area of
the filter medium that is exposed to the
flow of water from the pump, expressed
in square meters.
FILTER CARTRIDGE: A disposable porous
element made of paper or polyester and
is used as the filter medium in
cartridge-type filters.
FILTER CYCLE: The amount of time the
filter has water flowing through it each
day, expressed in hours.
FILTER ELEMENT: A device inside the
filter which is designed to trap
suspended solids as water flows through
it from the pool.
FILTER MEDIUM: The material used in the
filter to trap suspended dirt particles
as the water flows through it. It is the
polyester or paper in a cartridge filter
element, the sand in a sand filter and
the diatomaceous earth in a D.E. filter.
FILTER POWDER: A common name for
diatomaceous earth (D.E.), the filter
medium in a diatomaceous earth filter.
FILTER ROCK: Graded, rounded rock and/or
gravel which is used to support the sand
in sand filters.
FILTER SAND: Sand made up of hard and
sharp silica or quartz (or similar),
which have been graded for size and
uniformity, and is used as the filter
medium in sand filters. Nowadays it can
also refer to clinoptilolite, the
zeolite that is used as an alternative
to quartz as the filter medium in sand
filters.
FILTRATION RATE: The speed at which the
water is travelling through the filter.
It is expressed in liters per minute per
square meter of filter area or in
kiloliters per hour per square meter.
FLOC: See Flocculation.
FLOCCULANT: Also called a Flocculating
Agent. Virtually the same as a
coagulant, it is a chemical substance
(such as alum) that is used to clump
suspended particles or algae into a
heavy mass, which can be caught by the
filter or sinks to the bottom of the
pool for vacuuming.
FLOCCULATION: The combination, clumping
or coagulation of suspended particles so
that they form small clumps or "lumps"
(called floc).
FLOW RATE: The quantity of water flowing
past a specific point in a specified
time (e.g. the number of liters flowing
through the filter in 1 hour).
FOAM: A froth of bubbles on the surface
of the water. Usually comes from overuse
of algaecide but may also be caused by
soaps, oils or other contaminants
carried into the water by swimmers.
Enzymes may be used for foam control.
FREE AVAILABLE CHLORINE: The amount of
free chlorine in the pool water that is
available to oxidize, sanitise or
disinfect the water. The level can be
measured using a DPD1 test kit. It is
also called residual chlorine or
available chlorine.
GREEN HAIR: A condition caused by too
much copper in the pool water or very
high levels of chlorine.
GUNITE: A mixture of cement and sand
which is sprayed onto the iron
reinforced walls and floor of a hole to
build a pool. The gunite surfaces are
generally plastered.
GUTTER: Also called a Skimmer Gutter. An
overflow channel at the edge of the pool
through which floating debris, oil and
other things flow and empty into the
balance tank. Pools with gutters
generally do not have skimmers.
HALOGENS: The chemical elements in Group
VIIB of the Periodic Table of Elements:
fluorine, chlorine, bromine and iodine.
Only chlorine and bromine are used as
oxidizers, disinfectants and sanitizers
in swimming pools.
HAND SKIMMER: A net attached to a frame
which is then attached to a pole and is
used to remove large floating pollutants
such as leaves and insects from the
water's surface.
HARD WATER: Water that is high in
calcium, magnesium or other salts, which
makes it difficult for soap to lather.
Hard water also has a tendency to form
scale.
HARDNESS, calcium: The amount of calcium
dissolved in the water. It is usually
measured as calcium carbonate.
HARDNESS, total: The amount of calcium,
magnesium and other salts dissolved in
the water.
HERBICIDE: A chemical compound used to
kill or control plant or algae growth.
HYDROCHLORIC ACID: Also called muriatic
acid. A very strong acid used in pools
to lower the pH or total alkalinity. It
can also be used for cleaning an empty
pool (acid washing).
HYDROGEN: The lightest chemical element.
It is a component of water and a product
of many chemical reactions. pH is a
measure of positive Hydrogen ions in
water.
HYDROGEN PEROXIDE: An unstable,
colorless liquid which is used as an
antiseptic in the home. It can used as
an oxidising agent in pools. It is NOT
compatible with the Pool Wizard.
HYPOBROMOUS ACID: The active form of
bromine in water.
HYPOCHLORITE: The name given to a family
of chlorine compounds including: calcium
hypochlorite, sodium hypochlorite and
lithium hypochlorite. They are used as
oxidizers, disinfectants and sanitizers
in pool water.
HYPOCHLOROUS ACID: The active form of
chlorine in water.
IMPELLER: The rotating part of a pump
that is responsible for the movement of
water through the pump.
INLET: A fitting in the pool on the
water return line. Water is pumped back
into the pool through the inlet after
filtration .
IONISER: A water sanitizer that uses
electricity to generate metal ions,
usually copper and silver. It works by
passing a current through a set of
electrodes. The copper is an algaecide
and algaestat, while the silver is a
bactericide. Ionisers can significantly
reduce chlorine consumption. If the ion
levels get too high, problems with
staining or discoloration of the water
occur.
IRON: Iron is a natural element that can
cause the water to become clear brown or
green in color. It can also result in
staining of the pool surfaces. Iron can
be controlled by the addition of a
suitable sequestering or chelating
agent.
ISOCYANURATES: Also called stabilized
chlorine. A group of chlorine pool
sanitizers that contain stabilizer (cyanuric
acid or isocyanuric acid) to protect the
chlorine from the UV rays of the sun.
The most common types are dichlor and
trichlor. The granular form is dichlor,
while the tablet or stick form is
trichlor (usually used in a chlorine
feeder). Stabilized chlorine should be
used with care, to avoid problems such
as chlorine lock that may be caused by
overstabilisation.
J
K
L.S.I.: See Langelier Saturation Index
LANGELIER SATURATION INDEX: Also called
Langelier Index or Saturation Index.
This index can be used to determine
water balance according to the levels of
pH, Total Alkalinity, Calcium Hardness
and water Temperature. When all the
parameters are in balance, the water
will neither be corrosive or scaling.
LEAF NET: Also called a Hand Skimmer. A
net attached to a frame which is then
attached to a pole and is used to remove
large floating pollutants such as leaves
and insects from the water's surface.
LINER: Also called a vinyl liner. The
vinyl membrane that acts as the
container to hold the water in one type
of pool construction.
LIQUID ACID: Also called hydrochloric
acid or muriatic acid. It is used for
lowering pH, total alkalinity and for
acid washing.
LIQUID CHLORINE: Chemically, sodium
hypochlorite. It usually has 12% to 15%
available chlorine and has a pH of 13.
It is generally cheap, but difficult and
dangerous to handle. It also loses its
potency rapidly and is usually only used
in large commercial pools.
LITHIUM HYPOCHLORITE: A dry granular
chlorine compound with 35% available
chlorine and has a pH of 10.7 . It
dissolves quickly and can be used to
super chlorinate vinyl-liner pools,
painted pools and fiberglass pools.
MAGNESIUM HARDNESS: A measure of the
amount of magnesium dissolved in the
water. It is part of total hardness.
MAIN DRAIN: This usually refers to the
drain that is located in the deepest
part of the pool.
MAKE-UP WATER: Also called top up or
refill water. It is the water used to
replace water lost to evaporation,
splash-out, leaks and backwashing.
MARBELITE: Also referred to as Plaster.
It is a mixture of white cement and
white marble dust used as an interior
finish over the gunite or shotcrete of a
pool. It can be given a color or it may
be left white.
MARCITE: See Marbelite
MICRON: A unit of length equal to 1
millionth of a meter. Microns are used
to describe the pore size of filter
media. Sand filters have openings of 25
to 30 microns; cartridge filters have
openings of 8 to 16 microns; and D.E.
(diatomaceous earth) filters have
openings of 1 to 5 microns. Zeolite used
in sand filters have openings of 3 to 6
microns. A grain of salt is between 90
and 110 microns.
MICROORGANISM: An extremely small,
living breathing creature. The purpose
of disinfectants, sanitizers or
oxidizers is to destroy these creatures
in the pool water.
MINERAL: Substances such as Calcium,
Manganese, Magnesium, Nickel, Copper,
Silver, Zinc, Iron, Cobalt or Aluminum.
Their presence in high non-chelated
concentrations can lead to stains or
scale formation. The measure of water
hardness is dependent on these minerals.
MULTIPORT VALVE: Also called a 6-way or
6-port valve. Water from the pump can be
diverted for various functions by
turning the valve handle. The water may:
1. be sent to waste, 2. be used for
backwashing, 3. bypass the filter for
maximum circulation, 4. filter normally,
5. be used to rinse the filter, or 6.
the valve may have all its ports closed.
The pump must be off before changing a
valve setting.
MURIATIC ACID: Also called liquid acid
or hydrochloric acid. A very strong acid
used in pools to lower the pH and total
alkalinity. It can also be used for
cleaning an empty pool (acid washing).
NEUTRALIZER: A chemical used to
deactivate or destroy chlorine or
bromine. It is used in better test kits
in order to increase the accuracy of the
pool water tests.
NITROGEN: A gas that causes algae to
bloom and disables chlorine. It is
introduced into the water by rain and by
swimmers. Maintaining proper chlorine
levels will prevent nitrogen from
becoming a problem. Superchlorination
can destroy nitrogen and nitrogenous
compounds.
NON-CHLORINE SHOCK: A granular form of
potassium peroxymonosulfate (potassium
monopersulfate, potassium permonosulfate),
used to oxidize materials such as
microorganisms, contaminants (ammonia,
nitrogen, swimmer waste, ...) or
chloramines.
ORGANIC: Refers to chemical compounds
containing carbon atoms bonded together
with other elements. The main groups of
organic substances found in water are
proteins, carbohydrates, fats and oils.
ORGANIC WASTE: Also called swimmer or
bather waste. Refers to the soap,
deodorant, suntan lotion, body oils,
sweat, spit, urine . . . , that is
introduced into the water by swimmers,
as well as the leaves, dust and insects
that end up in the pool. The organic
waste may form undesirable chloramines,
which require large amounts of chlorine
or non-chlorine shock to be destroyed.
ORP: The abbreviation for
Oxidation-Reduction Potential. It is a
measurement of the oxidizer's (e.g.
chlorine) ability to oxidize
contaminants versus the contaminants'
(e.g. algae) ability to reduce the
oxidizer. It is an indication of the
level of free available oxidizer in the
water. ORP is generally used with
automated dosage systems and can give a
fair idea of the sanitation of the
water. It is not a measure of the total
or available chlorine. Sometimes called
Redox Potential.
OTO: The abbreviation for Ortho Tolidine.
A chemical reagent used to test the
total chlorine level in water at normal
temperatures. It can measure free
available chlorine if the water is first
cooled to 1�C. Its results depend on pH,
time and concentration of chlorine. Due
to its toxicity, the use of OTO is
restricted or prohibited in many western
countries.
OXIDATION: The burning up or destruction
of organic waste and organic compounds
in the pool water.
OXIDIZER: Any compound that removes or
destroys organic waste and organic
compounds in the water.
OZONATOR: An electrical device that
produces ozone that is introduced into
the water as a sanitizer.
OZONE: A molecule containing three atoms
of oxygen. It is known to be a very
powerful sanitizer. Ozone producing
equipment create this molecule by UV
radiation or corona discharge
generators.
PATHOGEN: Also called a pathogenic
organism. An organism that can cause
illness, disease or death.
pH: A term used to indicate the level of
acidity or alkalinity of water. A pH of
7.0 is neutral; below 7 is acidic; above
7 is alkaline or basic. pH is a
logarithmic expression of the measure of
positive Hydrogen ions in water. The
ideal range for pH in swimming pools is
7.0 to 7.6. The pH of our tears is 7.2
to 7.4 .
PHENOL RED: A chemical reagent dye used
to test pH. It can measure pH from 6.8
to 8.4 . The tablet form usually
incorporates a chlorine neutralizer for
more accurate results.
PHOTOMETER: An electrical instrument for
testing pool water conditions, which
measures the colors electronically
rather than visually, giving more
accurate results.
PLASTER: Also referred to as Marbelite.
It is a mixture of white cement and
white marble dust used as a finish over
the gunite or shotcrete of a pool. It
can be colored or it may be left white.
POLYMER: A large substance comprising of
small repeating molecules. Many
coagulants are made from organic
polymers as are algaecides and
algaestats.
POTASSIUM PEROXYMONOSULFATE: See
Non-chlorine Shock.
ppm: The abbreviation for parts per
million. It is a method of assigning
value to concentrations of chemicals in
the water. Many of the common pool water
tests, as well as acceptable ranges, are
stated as ppm. 1ppm = 1 mg/L
PRECIPITATION: To precipitate is to come
out of solution or to become insoluble
as a result of a chemical reaction.
Material forced out of solution will
settle, stain, scale or remain suspended
in the water.
PRESSURE GAUGE: A gauge with an dial
indicating the pressure in a closed
container such as a sand filter.
PUMP: A mechanical device which causes
water to flow under pressure for the
purpose of filtration or circulation.
PUMP CAPACITY: The volume of water a
pump is capable of moving during a
specified period of time. This is
usually given in liters per minute or
kiloliters per hour (m3/h).
PUMP CURVE: Also called a Pump
Performance Curve. It is a graph that
shows a pump's water flow capacity at
any given resistance.
PUMP STRAINER BASKET: A device placed on
the suction side of the pump, which
contains a removable strainer basket
designed to trap large debris in the
water flow without causing restriction.
Sometimes called a Pump Leaf Trap.
QUATERNARY AMMONIUM COMPOUNDS: Also
called Quats or QAC. A type of algaecide
composed of ammonia compounds. They are
also effective algaestats for certain
types of algae.
RATE OF FLOW: The volume of water
flowing past a point within a specified
time. Usually expressed as liters per
minute or kiloliters per hour (m3/h).
REAGENTS: The chemical indicators used
in testing various aspects of water
quality.
REDOX POTENTIAL: The abbreviation for
Reduction-Oxidation Potential. It is a
measurement of the oxidizer's (e.g.
chlorine) ability to oxidize
contaminants versus the contaminants'
(e.g. algae) ability to reduce the
oxidizer. It is an indication of the
level of free available oxidizer in the
water. ORP is generally used with
automated dosage systems and can give a
fair idea of the sanitation of the
water. It is not a measure of the total
or available chlorine. Sometimes called
ORP.
RESIDUAL BROMINE: The amount of free
available bromine remaining in the water
after the bromine demand has been
satisfied.
RESIDUAL CHLORINE: The amount of free
available chlorine remaining in the
water after the chlorine demand has been
satisfied.
SAND: The filter medium used by a sand
filter. It usually refers to quartz or
silica, but may also refer to zeolites.
SAND FILTER: A filter using sand, or
sand and gravel as the filter medium.
SANITIZE: To kill all microorganisms,
including bacteria and algae, and to
remove unwanted contaminants.
SCALE: The precipitate that forms on
surfaces in contact with water when the
calcium hardness, pH or total alkalinity
levels are too high. Scale may appear as
grey, white or dark streaks on the
plaster, fiberglass or vinyl. It may
also appear as a hard crust at the
waterline.
SCUM: The foreign matter which floats to
the surface of the water and forms a
layer or a film. It can also refer to a
residue deposited on the tiles or walls
of the pool.
SEDIMENT: The solid material that
precipitates out of the water and
settles to the floor of the pool.
SEQUESTERING AGENT: Also called
Chelating Agent. A chemical or compound
that combines with dissolved metals or
minerals in the water to prevent them
from coming out of solution, thus
coloring the water or causing stains.
SEQUESTRANT: A chemical which holds
metals in solution and helps prevent
scaling. See Sequestering Agent.
SHOCK TREAT: Adding large amounts of an
oxidizer such as chlorine, hydrogen
peroxide or potassium peroxymonosulfate
to the water to destroy ammonia and
nitrogen compounds, chloramines and
other contaminants.
SHOTCRETE: Similar to Gunite, but
premixed.
SKIMMER: A device installed in the wall
of a pool that is connected to the
suction line of the pump. The suction
pulls in water and floating
contaminants.
SKIMMER BASKET: A removable basket or
strainer placed in the skimmer, which is
designed to trap large solids from the
water before they get to the pump or
filter.
SKIMMER GUTTER: Also called a Gutter. An
overflow channel at the edge of the pool
through which floating debris, oil and
other things flow and empty into the
compensation tank. Pools with gutters
generally do not have skimmers.
SKIMMER NET: A net attached to a frame
which is then attached to a pole and is
used to remove large floating pollutants
such as leaves and insects from the
water's surface.
SKIMMER WEIR: The small floating door on
the side of the skimmer over which water
flows on its way to the skimmer. The
weir prevents debris from floating back
into the pool when the pump is off.
SLURRY: Water containing a high
concentration of suspended solids. D.E.
is usually added to the filter as a
slurry by mixing the D.E. in some water.
SODA ASH: Chemically, Sodium Carbonate.
A base that is used to raise the pH of
acidic (below pH 7.0) water.
SODIUM BICARBONATE: Also called Baking
Soda or Bicarb. A base that is used to
raise Total Alkalinity in pool water
with only a slight effect on the pH.
Sodium bicarbonate can only raise the pH
of the water to 8.5, regardless of the
amount used. Care should be taken,
however, to avoid adding large
quantities at one time.
SODIUM BISULFATE: Also called Dry Acid.
A granular form of acid used to lower
the pH or Total Alkalinity of pool
water.
SODIUM BROMIDE: A salt of bromine which
is used to raise the bromine levels in a
pool before using bromine tablets.
SODIUM CARBONATE: Also called Soda Ash.
A base that is used to raise the pH of
acidic (below pH 7.0) water.
SODIUM DICHLOR: A granular, stabilized
organic chlorine compound providing 56%
or 62% available chlorine that has a pH
of 6.9. Used for regular chlorination.
Should be used with caution for super
chlorination as it can cause the
stabilizer level to rise too high,
resulting in chlorine lock.
SODIUM HYPOCHLORITE: Liquid chlorine for
use in pools. It usually provides 12% to
15% available chlorine and has a pH of
13. It is generally cheap, but difficult
and dangerous to handle. It also loses
its potency rapidly and is usually only
used in large commercial pools.
SODIUM MONOPERSULFATE: Active ingredient
and chemical name of a non-chlorine
shock treatment or non-chlorine
oxidizer. See Non-Chlorine Shock.
SODIUM PERSULFATE: Active ingredient and
chemical name of a non-chlorine shock
treatment or non-chlorine oxidizer. See
Non-Chlorine Shock.
SODIUM SULFITE: A chemical that can be
used to neutralize chlorine or
dechlorinate pool water.
SODIUM THIOSULFATE: A chemical that can
be used to neutralize chlorine or
dechlorinate pool water.
SOFT WATER: Water that has a low calcium
and/or magnesium content. Soft water can
result in the etching of the pool's
surfaces, and should be increased with
calcium chloride.
SOLAR COVER: A floating pool cover that
increases the water temperature by
absorption and transmission of solar
radiation. It also reduces evaporation
and pollution from the environment.
SOLAR HEATING SYSTEM: A system that
consists of panels through which the
pool water passes to increase its
temperature by using the sun's heat.
STABILIZED CHLORINE: A family of organic
chlorine compounds that contain
stabilizer (cyanuric acid or
iso-cyanuric acid) to protect the
chlorine from the degrading UV rays in
sunlight. Most common types are dichlor
and trichlor. The granular form is
dichlor and the tablet or stick form is
trichlor.
STABILIZER: Also called Cyanuric Acid or
Conditioner. A granular chemical added
to the pool water which provides a
shield to chlorine for protection from
UV radiation. Too much can result in
chlorine lock.
STAIN: A discoloration or a colored
deposit on the walls or bottom of a
swimming pool. Stains are usually the
result of metals such as iron, copper or
manganese in the water. The stains may
be green, gray, brown or black. They may
discolor the water without affecting the
clarity. Sometimes a sequestering agent,
chelating agent or commercial
stain-remover may remove them. If that
doesn't work, the easiest way to remove
the stains is to drain and acid wash the
pool.
STAIN INHIBITOR: Also called a
Sequestering or Chelating Agent. A
chemical that will combine with
dissolved metals in the water to prevent
the metals from coming out of solution
and so avoiding dicoloration of the
water or stains.
SUPERCHLORINATION: Adding 7 - 10 times
the normal dose of chlorine to the water
to destroy ammonia, nitrogen,
chloramines and other contaminants.
SUSPENDED SOLIDS: Insoluble solid
particles that either float on the
surface or are in suspension in the
water causing cloudiness. They may be
removed by filtration, but if the
particles are too small a flocculant or
coagulant is necessary to enable the
filter to trap them.
TDS: See Total Dissolved Solids
TEST KIT: A manual or electrical device
used to measure specific chemical
residuals, levels or demands in pool
water. Kits usually contain reagents,
vials, titrants and color comparators
for the tests. The most common tests
are: pH, free available chlorine,
combined chlorine, total alkalinity,
calcium hardness, cyanuric acid and
metals.
TEST STRIPS: Small plastic strips with
pads attached that have been impregnated
with reagents to test pool water. The
strips are dipped into the water and the
resulting colors are compared to a color
scale to determine the values.
TIME CLOCK: Also called a Timer. An
electrical device that automatically
turns the pump or pool cleaner on or off
at predetermined intervals or times.
TITRATION: A method of testing for total
alkalinity, calcium hardness and
acid/base demand by adding a titrant,
drop by drop, until a color change is
observed.
TOTAL ALKALINITY: The total amount of
alkaline materials present in the water,
usually measured as carbonate
alkalinity. It indicates the water's
resistance to change in pH. Low total
alkalinity causes pH bounce. High total
alkalinity causes the pH to constantly
rise.
TOTAL CHLORINE: The total amount of
chlorine in the water. It is the sum of
free available chlorine and combined
chlorine.
TOTAL DISSOLVED SOLIDS: Also called TDS.
A measure of everything that has ever
dissolved in the water and all the
matter that is in solution. The only way
to lower TDS is to drain part of the
water and replace it.
TRICHLOR: A slow-dissolving, tablet or
granular stabilized organic chlorine
compound which provides 90% available
chlorine and has a pH of 2.9. It must be
dispensed using a floating feeder or an
in-line chlorinator. Trichlor contains
cyanuric acid that prevents the chlorine
from being destroyed by the ultraviolet
rays of the sun. When using trichlor,
the cyanuric acid level needs to be
checked regularly to avoid chlorine
lock.
TURBIDITY: The cloudy condition of the
water due to the presence of extremely
fine particles in suspension that are
able to pass through the filter. Adding
a flocculant or coagulant will clump the
particles together so they can be
trapped in the filter.
TURNOVER: Also called Turnover Rate. The
period of time, in hours, required by
the pump to circulate the volume of
water in the pool. Pool capacity in
kiloliters divided by pump flow rate in
kiloliters per hour (m3/h) will give the
turnover rate in hours.
ULTRAVIOLET LIGHT TREATMENT: Using UV
wavelength radiation to destroy
contaminants in water. UV light is also
used to create ozone molecules for the
same purpose.
UNDERWATER LIGHT: A light fixture
designed to illuminate a pool from below
the water's surface.
VACUUM: A device that uses suction to
collect dirt from the bottom and sides
of a pool. Most common is a vacuum head
with wheels that attaches to a pole and
is connected to the suction line. Some
automatic pool cleaners fall into this
category.
VINYL LINER: Also called a Liner. The
vinyl membrane that acts as the
container to hold the water in one type
of pool construction.
VIRUS: A pathogen capable of causing
disease.
WASTE GUTTER: The outer channel in a
pool with 2 gutters. The inner channel
(skimmer gutter) returns the water for
filtration, while the outer one collects
rain or wash water and diverts it to
waste before it can enter the pool.
WATER CLARIFIER: See Coagulant/
Flocculant.
WEIR: Also called a Skimmer Weir. The
small floating door on the side of the
skimmer over which water flows on its
way to the skimmer. The weir prevents
debris from floating back into the pool
when the pump is off.
X
Y
ZEOLITE: An alternative to quartz or
silica for use in sand filters. It is
typically clinoptilolite, the specific
zeolite suitable for pool water
conditions. Zeolite can provide
filtration down to 3 microns, is able to
absorb heavy metals such as iron or
manganese, and absorbs ammonia and
nitrogen compounds. Zeolite can also
absorb chloramines and is regenerated by
washing in salt. Being less dense than
quartz, 60% - 70% of the weight of
quartz is used. Zeolite is also claimed
to reduce backwashing by 50%.
SEE PHOTOS of our satisfied
customers' pools...
Matthews Pool Service
(916) 612-8877
CHECK OUT OUR
POOL SERVICES |