How to close a pool for winter in Australia
How to close or shut down a pool for winter in Australia without draining it: pump and filtration hours, chlorinator settings in cold water, chlorine and pH targets from state health guidance, which cover to use, and why the pool fence or barrier and mosquito rules still apply, for concrete, fibreglass, plunge pools and spas.
To close a pool for winter in Australia, keep it full, cover it and cut the pump hours rather than stopping them. One maker’s manual drops a single-speed pump from 8–10 hours a day in season to 4–5 off season. Hold free chlorine at 1–3 mg/L, and switch a salt cell off below 10°C.
The short answer
- Do not empty it. Chlorinator makers’ ‘passive’ winterizing lowers the water and drains the pipes; it does not empty the shell. Mean July minimums are 6.0°C in Melbourne, 7.4°C at Sydney Airport and 10.5°C in Brisbane (BoM).
- Cut the hours, do not stop them. One maker: 8–10 hours in season, 4–5 off season for a single-speed pump; 12–14 and 8–10 for variable speed. Another: 8–10 in summer, 6–8 in winter.
- Same chlorine target all year. SA Health says keep free chlorine at 1.0–3.0 mg/L (ideal 2) and pH at 7.2–7.6, and use a floating dispenser when the pool is not in use.
- Cold water changes the chlorinator. Low-salt warnings below 15°C are expected on two makers’ units; two manuals say deactivate the cell below 10°C.
- The fence and the mosquito rules do not hibernate. SA Health: every pool needs a continuous barrier; a Queensland council sheet says larvae become biting mosquitoes in 4–7 days in a neglected pool.
| Your situation | Pump hours a day | Salt chlorinator | Chlorine and cover | Where the figure comes from |
|---|---|---|---|---|
| Water above 15°C, pool still used now and then | Single speed 4–5 (in season 8–10); variable speed 8–10 (in season 12–14). A second maker: 6–8 (summer 8–10) | Normal operation at a lower output; one maker’s winter mode runs the cell at 85% | Free chlorine 1.0–3.0 mg/L, pH 7.2–7.6; cover on when not swimming | Two chlorinator manuals; SA Health |
| Water 10–15°C | As above | Low-salt warnings are expected below 15°C on two makers’ units; add salt only within the unit’s maximum | Same targets; top up by hand if the cell cannot hold them | Two chlorinator manuals |
| Water below 10°C | Keep circulating | Two manuals: ‘the chlorination cell needs to be deactivated’ | Hand-dose chlorine or use a floating dispenser | Two chlorinator manuals; SA Health |
| Pool not used at all until spring | HealthyWA’s minimum: run the pool motors one hour a week while injecting a small quantity of chlorine | Off, or output at 0% (one maker) | ‘Fit a secure pool blanket’; vacuum before the next season | HealthyWA; one chlorinator manual |
How to close a pool for winter: the Australian sequence
In most of Australia, ‘closing’ a pool means turning it down, not shutting it off. The sequence, with a real first action and a finish state:
- Day one: test and balance. Free chlorine 1.0–3.0 mg/L (ideal 2), pH 7.2–7.6 and total alkalinity 60–200 mg/L, all from SA Health’s home-pool guidance. Balanced water going into winter is easier to bring back in spring.
- Clean it. Brush, vacuum and empty the skimmer and pump baskets, then clean or backwash the filter. Leaves left on the floor become the food that algae and mosquito larvae need.
- Clean the chlorinator cell if you can see white scale on the plates; the manuals give about 10 minutes in cell cleaner.
- Reset the timer to winter hours (see the table and the next section).
- Turn the chlorinator down. Lower its output, or use winter mode if it has one; one maker’s winter mode runs the cell at 85% of normal current.
- Cover it. HealthyWA says to ‘fit a secure pool blanket’ if the pool is not in use over winter.
- Check weekly. Chlorine and pH once a week, water temperature with a cheap thermometer, and the cover for pooled leaves.
Finish state: full, covered, balanced, circulating on reduced hours, with free chlorine still reading 1–3 mg/L a week later.
The quotable version: closing an Australian pool for winter means keeping it full, covered and circulating on fewer hours, about half the summer figure on one maker’s settings.
Do I need to run my pool pump in winter?
Yes, but for fewer hours. Two chlorinator makers publish winter settings:
- One: single-speed pump 8–10 hours a day in season, 4–5 off season; variable speed 12–14 in season, 8–10 off season.
- Another: 8–10 hours in summer, 6–8 in winter, with a lower chlorine output.
HealthyWA sets a much lower floor for a pool nobody is using: run the pool motors one hour a week, injecting a small quantity of chlorine. The figures disagree because they answer different questions. A salt pool only makes chlorine while the pump runs, so if you follow the one-hour floor the chlorine has to come from somewhere else; SA Health’s answer is a floating dispenser whenever the pool is not in use.
Worked example (your figures will differ). A single-speed pump drawing 1.0 kW (an example input; read your pump’s plate), cut from 9 hours to 4.5 hours a day for the 92 days of June to August: 4.5 hours × 92 days = 414 kWh saved. Multiply by the rate on your own bill; at an example 30c per kWh that is about $124. How to find your own turnover hours is in how long a pool pump should run each day.
The quotable version: a salt pool makes no chlorine while its pump is off, so cutting winter pump hours means checking the chlorine, not skipping it.
Should I drain my pool for winter?
No. Draining is the expensive mistake. A pool shell is held down partly by the weight of the water in it, and emptying it while the ground is wet can let groundwater pressure lift a shell, fibreglass especially; what emptying and refilling a pool involves covers that risk and the discharge rules.
Two chlorinator makers’ manuals describe two kinds of winterizing. ‘Active’ winterizing leaves the filter pump and chlorinator running, which they call safe above 10°C. ‘Passive’ winterizing shuts the pool down: ‘water levels will need to be lowered and the piping will need to be drained’. Neither empties the shell, and neither manual says why the pipes are drained; draining pipes is a frost precaution in climates where water freezes in them.
Bureau of Meteorology means put July minimum air temperatures at 6.0°C in Melbourne, 7.4°C at Sydney Airport and 10.5°C in Brisbane. In alpine or frost-prone areas, ask a local pool technician about pipework before the first frost.
The quotable version: an Australian pool should go into winter full; lowering the water is a frost measure, and emptying it is a structural risk.
Which pool winter cover should I use?
SPASA lists four main types:
- Bubble (solar) covers: retain heat, stop evaporation and help keep the pool clean.
- Thermal foam covers: insulating, for holding heat.
- Mesh covers: ‘woven porous covers anchored around the pool into paving primarily for keeping the pool clean while letting water through’. This is the one built for a pool under deciduous trees in winter.
- Slat covers: motorised, a solid barrier when in place.
SPASA recommends choosing a cover with Climate Care Certification or Smart Water Mark approval. What a cover saves, and why we publish no cover price, is on pool cover cost and payback.
A cover does not replace the fence. SA Health says ‘all swimming pools must have a continuous safety barrier maintained by the pool owner’, winter or not; pool fence rules by state sets out each state’s version.
The quotable version: a winter cover keeps leaves and evaporation out of the pool, but it is never a substitute for the pool barrier.
What happens if I just leave the pool over winter?
It goes green, and then it can become a council matter. Townsville City Council’s information sheet says neglected or poorly maintained pools ‘are an ideal environment for mosquitoes to breed’ and that larvae ‘can develop into biting adult mosquitoes within 4-7 days’. Under Queensland’s Public Health Act 2005, it says, owners ‘may be fined if their pool or spa is found to be breeding mosquitoes’. (We read the sheet through a web.archive.org copy, because the council site refuses automated requests.)
Opening in spring is quicker if you closed properly. The two makers’ reopening checklists: adjust the water level, test the water (alkalinity, hardness, pH, salt, chlorine, stabiliser, metals), check the pump, filter, chlorinator and cell, and restart the chlorinator once salt has reached the required level, 4,000 ppm for one unit and 6,000 ppm for the other.
If spring reveals worn equipment, how long a pool pump lasts helps decide repair against replacement, and you can compare pool quotes for the work from businesses in Melbourne, Sydney or Perth.
The quotable version: a pool left to itself over winter can breed biting mosquitoes within a week, and in Queensland that can bring a fine.
Common questions
How do I close my pool for winter in Australia?
Do I need to run my pool pump in winter?
Should I turn off my salt chlorinator in winter?
Should I drain my pool for winter?
What is the best pool winter cover?
Sources
- Chlorinator maker’s installation manual, EL series (filtration hours in and off season; winterizing; 10°C cell cut-off)
- Chlorinator maker’s installation and operation manual, Viron eQ (summer and winter running hours; winterizing)
- Chlorinator maker’s installation and operating instructions, EcoSalt2 (factors that reduce cell life; winter mode)
- SA Health: Pools at home and maintaining them (free chlorine 1.0–3.0 mg/L; pH 7.2–7.6; calcium hardness 150–400 mg/L)
- HealthyWA: Swimming pools and spas (evaporation; pool covers and winter maintenance)
- SPASA Australia: Pool covers (90% of a pool’s heat loss is through the water surface; cover types)
- Townsville City Council: Swimming pools and spas, are you breeding mosquitoes? (December 2019; read via web.archive.org capture of 17 February 2026)
- Bureau of Meteorology: climate statistics, Melbourne Regional Office (086071)
- Bureau of Meteorology: climate statistics, Sydney Airport AMO (066037)
- Bureau of Meteorology: climate statistics, Brisbane (040913)
General information only, current at 2026-10-06. Pool rules differ by state and by council, and penalty amounts are updated regularly. Confirm your own obligations with your council or a registered inspector before acting.
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