As the weather cools and swimming becomes less frequent, many pool owners start wondering how to adjust their maintenance routine—especially when it comes to the pool pump. How many hours should you run your pool pump in autumn? Keeping the water clean is still important, but you don’t want to waste energy running the pump longer than necessary.
In this guide, we’ll walk you through why autumn is the perfect time to adjust your pump hours, how to find the right balance between water quality and energy efficiency, and what to keep in mind as winter approaches.
Why Should You Adjust Pool Pump Hours in Autumn?
During summer, your pool pump works hard to circulate water, evenly distribute chemicals, and filter out debris. But as the seasons change, so do your pool’s needs. Here’s why you can reduce pump hours in autumn:
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Cooler temperatures slow algae growth: Algae thrive in warm water, so as things cool down, the risk of green pool water naturally decreases.
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Less pool use means less chlorine demand: With fewer people swimming, there’s less sunscreen, body oils, and dirt entering the water, resulting in a lower level of sanitisation required to keep the pool healthy.
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Energy savings add up: Running your pool pump less can lead to noticeable savings on your electricity bill, without compromising water quality.
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Lower sunlight (ultraviolet light): Chlorine can be quickly broken down by sunlight (that's why we often add a chemical called stabiliser to slow this rate of degradation down). As the sunlight becomes less harsh, we don't need to produce as much chlorine.
Given these factors, autumn is the perfect time to start reducing your pump hours gradually while keeping an eye on water clarity.
What’s the General Rule for Pool Pumps in Autumn?
The general rule for pool pump operation is that all the water should pass through the filter at least once per day. In summer, that often means 8 to 10 hours of runtime, depending on your pool size and location. But in autumn, with cooler temperatures and less pool activity, you can cut back significantly.
Here's a general guide to help you adjust your pump runtime based on pool size:
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Small pools (up to 30,000L): 4–5 hours per day (6–8 in summer)
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Medium pools (30,000–50,000L): 5–6 hours per day (8–10 in summer)
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Large pools (50,000L+): 6–7 hours per day (10–12 in summer)
These are general guidelines. Every pool is different, so factors like your filtration system, local climate, and whether you use a pool cover will influence the ideal runtime.
How to Adjust Your Pump Hours Gradually
Rather than cutting your pump runtime in half overnight, reduce it by 30 minutes per week while monitoring your water quality. If the water stays clear and chemical levels remain stable, you’re on the right track. If you start noticing cloudiness or an increase in debris, bump the hours back up slightly.
What Affects Pool Pump Runtime in Autumn?
There’s no one-size-fits-all answer to knowing how many hours to run a pool pump in autumn—it depends on several key factors:
1. Pool Size and Filtration System
Larger pools require longer pump cycles to ensure proper water circulation, while smaller pools can get away with shorter runtimes. If you have a high-efficiency filter or a variable-speed pump, you may be able to reduce your hours even further.
2. Local Climate
In warmer regions, including parts of Western Australia, autumn temperatures can still be mild, meaning algae growth is still a concern. If your area experiences slow, gradual cooling, you may need to keep your pump running a little longer than in places where autumn brings a sudden temperature drop.
3. Pool Cover Usage
Using a pool cover significantly reduces debris and evaporation, meaning the pump doesn’t have to work as hard. If you keep your pool covered most of the time, you can safely reduce the filtration hours. However, the downside of the pool cover in cooler months is that the chlorine levels can build up dramatically, and when you use a pool cover this can affect run times.
4. Water Quality Monitoring
The best way to determine if your pump is running enough is to test the water regularly. If you notice cloudy water, debris buildup, or chemical imbalances, your pool may need more filtration. Keep an eye on your chlorine and pH levels to ensure they remain stable.
Keeping Your Pool Clean While Saving Energy
Cutting back on pump hours in autumn doesn’t mean neglecting your pool. Here’s how to maintain water quality while reducing energy use:
1. Run the Pump During Daylight Hours if Using PV Panels
If your home is equipped with PV (photovoltaic) solar panels, it's most efficient to run your pool pump during the day. This is when your panels are actively generating electricity, allowing you to power the pump using solar energy and minimise reliance on the grid.
2. Use a Variable-Speed Pump
If you have a variable-speed pump, consider lowering the speed instead of drastically cutting hours. Running the pump at a lower speed for longer can be more energy-efficient than short bursts at full power.
3. Regular Skimming and Brushing
With reduced pump hours, manual pool maintenance becomes even more important. Skim leaves off the surface, brush the pool walls, and vacuum as needed to prevent debris buildup.
4. Keep an Eye on Water Clarity
If your pool starts looking cloudy or develops algae, increase the pump hours slightly until the water clears up.
Preparing for Winter: What’s Next?
As autumn progresses and temperatures drop further, many pool owners are beginning to prepare their pools for winter—especially if they don’t plan on swimming again until spring with the colder weather.
1. Reduce Pump Hours Further
Once the weather cools significantly and swimming stops entirely, you can drop your pump hours to as little as 2–4 hours per day, depending on the size of your pool.
2. Keep Chemicals Balanced
Even if you’re not using the pool, it’s important to check and balance the water chemistry every couple of weeks. Proper chlorine and pH levels will prevent algae growth and bacterial buildup.
3. Clean and Inspect Your Equipment
Autumn is a great time to give your pump, filter, and skimmer baskets a good clean. Checking everything now can help prevent costly repairs when spring comes around.
Get Your Pool Sorted for The Off-Season with Pool Assist
Wondering how many hours to run your pool pump in autumn? Most pools can safely reduce runtime to 4–6 hours per day, adjusting as needed for water clarity and debris levels.
By cutting back gradually, using a pool cover, and monitoring water chemistry, you can keep your pool clean while saving on electricity. Fine-tuning your pump settings now will make the transition into winter much easier.
Need expert help? Get in touch with our team at Pool Assist, or pop into our store for tailored advice. Let us take the hassle out of pool care and keep your system running smoothly.