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How a Swimming Pool Works

As a new pool owner, either from buying a property with an existing swimming pool, or by having a pool built. It can be confusing as to how it works and what all the equipment does. At 1st-direct.com we recognise this and we have constructed the following guide for the new pool owner.

Types of In-Ground Swimming Pools

There are different types of in-ground swimming pools, Concrete, - Liner, - One piece pools, are three popular ones.

Concrete pools are made using concrete blocks built on a concrete floor, or solid concrete walls and floor blown or sprayed onto a steel framework. The internal finish is either mosaic tiles, a marble finish or just a special paint finish.

Liner pools consist of a plastic sheet vacuumed into a shell, this shell can be constructed from block work, fibreglass or steel panels and the internal finish is the plastic liner, this may be a plain colour or one of the numerous patterns that are available.

One piece pools are usually made from a fibreglass based compound and have an internal finish of the smooth fibreglass or can be mosaic tiles. A 'Swim Spa' which is part pool and part spa is also a One piece pool. One piece pools are the complete swimming pool in one piece, these are normally craned into position.

In the Swimming Pool

A Main Drain, Drain or Sump is the suction fitting located in the floor of the pool, this will normally be in the deepest part and there are quite often more than one.

A Low Suction is fitted in the wall and may be under the skimmer, this is normally fitted as the 'second' drain or may be standard on some panel pool kits.

A Skimmer, will be fitted in the wall, at the water level, normally this will be near the end of the pool wall, again there may be more than one fitted.

A Return, Inlet or Eyeball Inlet will be fitted through the wall, normally the end wall and can be anywhere from 300mm below the surface. Again there may be more than one in the pool and they can be at opposite ends.

A Vacuum, or Pool Cleaner line will be fitted through the wall and will be half way along the longest wall and should be about 150mm below the water level, this may have a threaded plug in it when it is not being used.

An Automatic Top up is a fitting like the skimmer, fitted into the pool surround next to the coping (edge) stone, it houses a ball valve and there is a pipe going through the pool wall. (Looks like another return fitting) Used to automatically keep the pool water at the correct level.

An Underwater Light is fitted through the pool wall and there will be a Deck Box in the paving directly above it, this houses the low voltage electrical connection, this should illuminate the whole of the pool water, again there may be more than one fitted. More recently built pools may have Fibre Optic lighting with an Illuminator, this will produce subtle 'mood' lighting in and around the pool area.

In the Plant Room (Where the pump and filter are housed)

• Pump
• Filter
• Heater
• Pipe work, valves and any other machinery

Maintenance Equipment and Covers

• Vacuum Hose
• Vacuum Head
• Wide Brush
• Net, flat and/or deep
• Telescopic Handle - any other attachments
• Pool Roller/Reel system - for cover
• Summer cover - could be bubbles or foam type material
• Winter cover - porous material with steel fixings or plastic sheet and long tubes.
• There may be an electric 'all year' cover and an automatic pool cleaner

Chemicals

ALWAYS READ THE LABELS & NEVER MIX CHEMICALS

These are the most likely ones you will come across:

• Stabilised Chlorine as Granules or Tablets.
• Shock Chlorine as a liquid in 5 or 20 litres or in Granular form.
• Algaecides normally these are liquid, in 1,2, 3 or 5 litre containers.
• pH Minus : (pH-) : (pH/TA-) : Dry Acid : pH & Alkalinity Reducer : Sodium Bi-Sulphate
• pH Plus : (ph+) : pH Increaser : Soda Ash : Sodium Carbonate.
• TA Plus : (TA+) :TA Increaser : Alkalinity Increaser : Sodium Bi-Carbonate.

The following are others that you may need or see advertised:

Hardness Increaser : Clarifier : Flocculent : Stain and Scale chemicals : Tile and Liner cleaners : Pool Stabiliser/Conditioner - Cyanuric Acid : Bromine : Baquacil : Baquashock : Salt and many other chemicals in multi-branded forms.

ALWAYS READ THE LABELS & NEVER MIX CHEMICALS

All the fittings in the pool are connected to pipes that then run underground to the plant room where they terminate at either gate valves or ball valves, the suction pipes from the drains, skimmers and vacuum point are all valved and then connected together and are fitted to the 'front' of the Pump, the pipe then runs from the top of the pump to a multi port valve which is connected to the Filter. There are another two pipes coming out of the multi port valve, one runs to a drain or waste pipe (Backwash) and the other (Return) travels to a heater followed by an automatic cleaner pump (where fitted) and then to any automatic chemical dosing equipment before travelling underground to the pool and terminating at the returns (inlets).

The Pump pulls the water from the pool, it passes through the 'wet end' of the pump where there is a Coarse Strainer basket, this end of the pump usually has a clear lid allowing vision and access to empty any debris in the water, that has been trapped whilst passing through the pump on its way to the filter. The water is then pushed to the multi port valve where it is directed into the top of the filter, it is then forced through the filter media or cartridge which entraps the smaller debris and very small particles in the water, it is then pushed from the bottom of the filter back to the multi port valve and is directed through the return pipe, it is then pushed through the heater, where it gains temperature from the heater before being pushed back to the pool via the return pipe. This filtered and heated water then mixes with the rest of the pool water and is being moved through the pool to eventually travel the coarse again. If there is automatic chemical dosing equipment installed, this will be infused into the 'return' water after it has passed through the heater.

The Pump

The Pump is the driving force of the swimming pool water circulation.

It consists of a motor and a 'wet-end' the motor drives an impeller which pulls the water from the pool and pushes it through all the equipment and back to the pool.

The Filter

There are numerous types of filter, the following three are:

Sand Filter - this is the most widely used in the UK - easily cleaned. This filter can take other forms of media instead of sand.

Cartridge Filter - this will filter out smaller micron debris than sand - not so easy to clean.

Diatomaceous Earth Filter (material encased plastic sceptums coated with powder DE) - this will filter out the smallest micron debris but can be problematic regarding disposal of the spent 'earth' and messy when recharging sceptums.

The Pool Heater

There are numerous methods of heating your swimming pool water, the most common being a direct form of heating using fossil fuel.

Direct Gas Heater: this is a heater that uses either Natural Gas or Liquified Petroleum Gas (LPG) The pool water passes through the heater where the flames from the burning fuel directly heats the pool water.

Direct Oil Heater: this works the same as the Gas heater above.

Heat Exchanger (Calorifier): This uses heat from your existing indirect house boiler. This heater is basically a cylindrical unit containing a separately sealed tubed unit within. The pool water (Secondary) passes through the tubed unit whilst the house boiler water (primary) passes on the outside of the tubed section in the unit and the heat is transferred from the primary water through the nickel plated tubes to the secondary (pool) water.

Electric Heater: (direct) This heater has an element similar to an electric kettle, but obviously larger and more robust. The pool water is pushed through the heater and it is deflected on its entry to enable it to pick up the maximum amount of heat from the element before exiting the heater.

Heat Pump: (Indirect) This heater uses a Calorifier (exchanger) to transfer self generated heat from compressing gas and ambient air temperature as the primary heat and transfers this to the Pool water as the secondary. The unit works like a refrigerator in reverse.

Solar Heating: This means of heating is accomplished by the use of Solar Panels that have the swimming pool water passing through them whilst the actual panels are absorbing any heat obtainable from the Sun and the ambient air.

Solar Cover: This is a cover that floats on the surface of the pool, the material is made from plastic with sealed air bubbles across the entire cover. the bubble side of the cover rests on the water and when the sun heats the cover, the heat is transferred through the bubbles to the pool water.