Pool Spa Life
Pool Spa Life

Pool & Spa terminology

Definitions of commonly used pool and spa terminology.




Hydrochloric Acid. To lower pH and/or Total Alkalinity


A chemical to kill and prevent algae in pools


Chemical introduced by swimmers which forms Chloramines


On a multiport valve. To clean the filter

Black spot algae

A common type of algae found in pools


A sanitiser used in heated indoor pools

(Sodium Bicarbonate)

Buffer slows down the change of pH in pool water

The ideal level is 80 to 120 ppm

Calcium Chloride

The chemical that is added to increase Calcium Hardness

Calcium Hardness

A measure of Calcium in the pool which protects the pool surface and is part of water balance

Calcium Hypochlorite

A common Chlorine sanitiser


Used in a cartridge filter


Where Chlorine is generated in a salt chlorinator

Cell cleaner

A chemical to clean the scale from salt cells

Usually Phosphoric acid based


A chemical formed by Chlorine and Ammonia, which causes sore eyes, itchy skin and makes the pool smell strongly of Chlorine

Removed by superchlorination


The most common sanitiser used in pools

Can be liquid or granular

Chlorine remover
(Sodium Thiosulphate)

A chemical to remove excess Chlorine from water

Citric Acid

Chemical used to remove stains


A chemical to clear cloudy water

Cyanuric Acid

See Stabiliser


Movable return to pool

Where water returns to the pool

Filter aid

A powdered chemical to aid filtration

Filter cleaner

A proprietary product to clean cartridges and sand filters


A chemical to clear very cloudy water

Alum in powder or liquid form

Glass Media

Type of media used in a media filter

Granular chlorine

See Calcium Hypochlorite

Green algae

The most common type of algae found in pools

Hardness increaser

See Calcium Chloride

Heat pump

Water heater using heat from the air

Instant pellets

A chemical used for boosting Chlorine levels and used for superchlorination


An electronic device to purify pool water

Leaf rake

Device for removing leaves from the bottom of a pool

Leaf scoop

Device for removing leaves from the pool surface

Leaf shovel

Device for removing leaves from the bottom of a pool

Leak sealer

A chemical to stop leaks in pools

Liquid Chlorine
(Sodium Hypochlorite)

A sanitiser

Lithium Hypochlorite

Sanitiser used in spas


See ppm

Main drain

In the bottom of the pool

A relief valve

Multiport valve

Valve on a media filter to direct water flow

Mustard algae

A rare type of algae found in pools

"O" ring grease

Special waterproof silicone grease

Once a week tablets

(Trichlor, TCCA)

Slow dissolving tablets used in a floating dispenser

A sanitiser


An electronic device to make Ozone which purifies pool water


A measure of acid or alkali in pool water

The ideal pH is 7.2 to 7.6


Parts per Million. Concentration

Also, milligrams per litre, mg/litre


A mineral food that algae needs to grow

Phosphate remover

A chemical to prevent algae growth; to remove phosphates


An organic chemical sanitiser

Pool alarm

Device that sounds an alarm when a child falls into a pool

Pool cleaner

A device to clean the pool

Either suction, robotic or pressure cleaner

Pool cover

Plastic Cover used to control heat loss from the pool

May also be a safety cover

Pressure gauge

Gauge on top of the filter to tell you when to clean it

Pump basket

A plastic basket in the pump, which collects leaves

Pump lid "o" ring

Rubber ring around the pump lid which needs greasing regularly, to stop air leaks


On a multiport valve

The water by-passes the filter


See eyeball


Used by a salt chlorinator to make Chlorine

Salt Chlorinator

An electronic device to make Chlorine from salt in the water

Salt level

Salt content of pool water, needed by the salt chlorinator


Specially graded sand for a media filter


A chemical that kills harmful bacteria; usually Chlorine


Scale, a Calcium Carbonate (chalk) build up on salt chlorinator cells and pool walls


See Stabilised Chlorine

Skimmer basket

A plastic basket in the skimmer box, which collects leaves

Skimmer box

At the side of the pool. Where water is skimmed from the surface

Skimmer sock

A sock put over the skimmer basket, to remove fine particles

Sodium Bicarbonate

See Buffer

Sodium Hypochlorite

See Liquid Chlorine

Stabilised Chlorine


A common Chlorine sanitiser


(Sunscreen, Cyanuric Acid)

A chemical to stop Chlorine loss by sunlight. Liquid or granular

The ideal level is 30 to 50 ppm

Stain remover

A chemical to remove stains (usually brown Iron or Manganese) from the pool surface


See Stabiliser

Telescopic pole

Extendable pole for attaching pool accessories

Test Kit

A 4 in 1 kit to test Chlorine, pH, Total Alkalinity, Acid Demand

Tile and vinyl cleaner

Chemical to clean the water line of a pool


Standalone or part of the salt chlorinator

To regulate the pump hours

Total Alkalinity
(TA )

A measure of the amount of alkaline (see Buffer) in the water

The ideal level is 80 to 120 ppm

Vac head

Attached to the telescopic pole to clean the floor of a pool

With wheels for concrete pools or brushes for fibreglass, vinyl and painted pools

Vac hose

Special flexible hose for vacuuming the pool

Vac plate

A plastic disc, placed in the skimmer box when vacuuming, which the vac hose is connected to


Sucking dirt and debris into the filter

Cleaning the pool


On a multiport valve

Water goes down the drain

Water balance

Balanced water is safe to swim in and protects the pool surface and fittings

Water flow control valve

Valve used to control the suction (and speed) of a cleaner

Weir door

For debris floating on the surface to be removed from the pool more easily than without it, as well as keeping that debris in the skimmer basket area so that it can be removed later.


When the pool is not used, in winter


A type of media used in a sand filter

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