Applied Environmental Health ~ Environmental Services

Guide for private swimming pool owners

  (PDF version)

This guide provides important information for owners, operators and users of private swimming pools (definition).

The most important factor in swimming pool care is to keep the water clean and disinfected at all times.

A well maintained swimming pool can provide many hours of enjoyment. However, if a swimming pool is not properly looked after, it can be a source for harmful miro-organisms, which may cause illness.

The correct use of swimming pool water chemicals and good management of the disinfection, filtration and recirculation system will keep the swimming pool water in a clean, safe and healthy condition.

Why is safe water in swimming pools so important?

If a swimming pool is not kept clean and properly disinfected, the water may become contaminated with bacteria or other micro-organisms. Contact with contaminated swimming pool water can lead to:

• skin, ear and eye infections
• gastro-intestinal infections (stomach upset).

How to keep the swimming pool water safe

Proper disinfection and filtration of the swimming pool water kills harmful micro-organisms, removes body fats and oils, and ensures the water is clean, safe and sparkling.

Swimming pool water should be tested prior to use and at least three times per week using a reliable pool water test kit, as advised by your pool supplier. When testing the following parameters should be measured; disinfection levels, pH and total alkalinity.

It is very important that the pump lint-pot and filter are cleaned regularly to ensure they do not become a source of contamination for the swimming pool water.

If a sand or diatomaceous earth filter is used, the water used to backwash (rinse) the filter must be disposed of into the sewer or into separate underground soakage if located in an unsewered area.

Disinfection agents

Use only commercially available disinfectants suitable for private swimming pools. Chlorine is the most common. Other methods include ozonation, UV irradiation and ionising systems.

Note: Ozone, UV and ionising systems require the addition of a small amount of oxidising agent such as chlorine or hydrogen peroxide to maintain a residual disinfection activity in the water.

The ideal disinfection system is one that uses automatic dosing and filtration. However, manual dosing is commonly used in private swimming pools. When using manual dosing, it is important to check the pump and filter system daily to ensure they are clean and working correctly.

A method such as a floating immersion dispenser should be used to disinfect the swimming pool water at all times when the pool is not in use. Consult with the swimming pool supplier for manual operation requirements.

When the swimming pool becomes heavily contaminated or is poorly maintained it may need to be "shock dosed" to bring it back to the correct operating conditions (see below).

Recommended disinfection levels for swimming pools

Chlorine disinfection:

• not less than 1 mg/L and up to 3 mg/L residual free chlorine* while the pool is in use. The ideal level is 2 mg/L.

Other agents:

Consult with the supplier of the disinfection agent for details.

Note:    (1) mg/L (milligrams per litre) is the same as ppm (parts per million).

(2) skin or eye irritation associated with a strong chlorine like smell can actually be caused by insufficient residual chlorine levels with the smell due to too much combined chlorine instead of free chlorine.

* Residual free chlorine is chlorine left over after combining with organic matter in the swimming pool.  This residual chlorine is free to kill bacteria from the bather or other sources.

Shock dosing

To do this using chlorine:

• use a metric measuring jug or scales to add a sufficient quantity of chlorine (or other suitable oxidising agent) to the water to achieve 10mg/l residual free chlorine; eg. add 200 mL of liquid sodium hypochlorite (12.5% available chlorine) or 30 g of granular calcium hypochlorite per 1000 litres of water.
• ensure 10mg/L residual free chlorine is maintained for at least one hour.
• operate the pump and filter at all times during shock dosing.

Other products may be available for this purpose. Consult with your pool supplier.

Caution: Do not use the swimming pool until residual free chlorine falls to 4mg/L.

pH

Swimming pool water must be within the following pH range of 7.2 to 7.6 when using chlorine for the disinfectant to work efficiently.

Total alkalinity range

Total alkalinity prevents cloudy water, scale formation, corrosion of metals and makes the water comfortable.  To adjust, add sodium bicarbonate as advised by the supplier.

Total alkalinity of the water should be checked weekly to ensure the following levels:

• for chlorine disinfection: 60 mg/L to 200 mg/L.

Note: When adding chemicals to pool water, first add the chemicals to water in a bucket, then add the mixture to the pool water with the pump and filter operating. Add small quantities at a time. Wait 10 to 15 minutes

Water temperature

When a domestic swimming pool is heated check the temperature regularly and maintain it at a suitable comfort level, usually 26^oC to 35^oC.

Water temperature and other factors affect disinfection and this should be adjusted to ensure recommended values are maintained.

Water temperature should not exceed 37^oC as it will cause discomfort for the person using the swimming pool and may even cause increased body temperature (hyperthermia).

If the pool is continuously heated it will require continuous disinfection.

Topping up the pool

The water in a domestic swimming pool should be topped up and the disinfection levels and pH checked regularly. In accordance with SA Water restrictions the level of water in a swimming pool that has been previously filled with water may be topped up or maintained only with water from a hand held hose or bucket. All top up water should be added via the skimmer box with the filtration system running. For further information on the SA Water restrictions please see www.sawater.com.au/sawater or freecall 1800 130 952.

If algae are present ensure the disinfectant and pH levels are in accordance with the recommended range. If algae are present in high numbers super chlorination and manual removal may need to be considered. Ensure the area is well ventilated. If algae persist the addition of an algaecide may be required. A pool chemical supplier should be consulted.

When NOT to use the swimming pool

Swimming pools should not be used:

• if the disinfectant level and/or pH is not within the recommended range or the pool water is dirty or cloudy
• if the filtration unit and recirculation pump are not operating properly
• by persons who are under the influence of alcohol or taking drugs that cause drowsiness
• by persons with open wounds or who feel unwell.

Persons who are immunocompromised are advised to check with their doctor before using a swimming pool.

General rules for using a swimming pool

• Always supervise children using the swimming pool.
• Do not use a swimming pool that is not properly maintained.
• Ensure compliance with fencing requirements.  Contact your local council for details.
• Cleaning the swimming pool

The swimming pool should be cleaned regularly including vacuuming and scrubbing the walls.  Backwashing should be undertaken at least weekly.

Definition

A private swimming pool is one that is available only for the use of the owner/occupier and invited guests in a private home. It does not include a communal swimming pool in flats, units, retirement villages, and the like, under the care and control of a corporate body.

For more information on maintaining your swimming pool, contact your swimming pool retailer, local council Environmental Health Section or the Environmental Health Service, Department of Health.

Produced by the Environmental Health Service, Department of Health and the Swimming Pool & Spa Association of Australia

For information on public pools refer to the SAHC Codes | Return to top

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