Is a pool cover worth it in a subtropical climate?

A pool cover is worth it for most Sunshine Coast owners who want warmer water in the cooler months, less top-up water and less leaf litter, but it adds a daily routine and it is never a safety barrier. This guide sets out what each cover type does, which one matches your goal, and how to live with it in a subtropical backyard.

Is a pool cover worth it? The short answer for warm-climate owners

Yes, a pool cover is worth it for a warm-climate pool when your goal is a longer swim season, less evaporation or less cleaning, and it adds little value if you rarely uncover it or your pool is already too warm in summer. The value of a cover comes from what it stops: heat escaping at night, water evaporating in the sun and wind, and leaves and dust landing in the water. The Australian Government’s Your Home guide says covering a pool and lowering the water level can save up to 30,000 litres of water a year, and that covers significantly reduce evaporative losses.

The honest trade-offs matter just as much in a subtropical climate. A solar cover on the Sunshine Coast in January can push water past comfortable swimming temperature, so many owners leave it off for parts of summer. And no cover replaces a compliant pool fence. If you will use a cover most days for at least part of the year, it usually earns its place. If you will not, spend the effort on a heating plan or a regular pool maintenance routine instead.

What a pool cover actually does: heat, evaporation, debris and chemicals

A cover earns its keep mainly through the heat it holds and the water it saves; keeping debris out and cutting chlorine loss to the air are useful extras. How much each job matters depends on the cover type and on your pool’s exposure to sun and wind.

• Heat. A clear or translucent bubble cover lets sunlight through into the water and then holds that heat in. Daisy Pool Covers, an Australian cover manufacturer, says its bubble covers let the sun heat pool water by up to 8°C and retain heat by insulating the pool overnight. Treat that as a manufacturer’s upper figure, not a promise for every pool.
• Evaporation. Water loss depends on the pool’s surface area, the water and air temperature, humidity and wind, according to the same manufacturer’s water-saving guidance. A cover sits between the water and the sun, wind and dry air, which slows that loss. Your Home notes that around 40% of household water is typically used outdoors and that pools contribute to high outdoor use.
• Debris. Leaves and dust land on the cover instead of sinking, which means less work for your skimmer, filter and cleaner.
• Chemicals. Chlorine gasses off from an open surface. With a cover on, more of it stays in the water, so readings run higher and you need less to hold the same level.

What a pool cover does not do is make a pool safe for unsupervised children, fix a chemistry or filtration problem, or heat water on cloudy days with no sun to capture.

Types of pool cover compared: solar bubble, thermal foam, leaf/debris and automatic

For most outdoor pools a solar bubble cover is the type worth starting with; thermal foam, leaf or debris and automatic slat covers are worth it when you have the specific job each is built for. The table compares the factors that decide fit. It does not rank them, because the right cover depends on what you want from it.

Daisy also describes its foam range as suited to pools heated by an external source such as a heat pump, to cooler climates, indoor pools and overnight use, and its leaf cover as letting water through while debris and dust stay out, which it says also reduces evaporation. Automatic slat covers open and close by remote or wall key. An automatic cover that is hard-wired must be connected by a licensed electrician, as Queensland’s Electrical Safety Office requires for hard-wired appliances.

Which cover suits your goal? A decision table

The cover that suits you is the one matched to your main goal, so start with what you want to change and read across. Most Sunshine Coast owners have one main goal and one secondary goal; pick the cover for the main one.

If the goal is warmer water all year, a cover is part of the answer rather than the whole answer. Compare it with the options in the solar pool heating guide and on our pool heating page.

Pool covers in Sunshine Coast conditions: sun, storms and year-round swimming

On the Sunshine Coast a pool cover is worth most in the cooler months and through storm season, and least in the height of summer. In a subtropical climate where many owners already swim for much of the year, the main gain is more comfortable water in late autumn, winter and early spring rather than a dramatically longer season.

Summer heat cuts the other way. Cover maker Daisy notes it is quite normal for a covered pool to reach 30°C or more in mid-summer, and advises taking the cover off when the air temperature goes above 35°C and storing it somewhere protected and cooler. That is a real consideration on a hot, still January week.

Storm season brings two practical issues. First, heavy rain lifts the water level, and if a cover edge rises above the coping, wind can get under it, the maker warns. Second, storms drop leaves and debris, which a cover keeps out of the water if it is on. Before a forecast storm, check the water level and either secure the cover or roll it away. For cover advice, visit our shop in Noosa, Maroochydore or Caloundra.

Living with a cover: rollers, daily routine and how long to leave it on

A cover is only worth it if it goes back on after every swim, and a roller is what makes that routine stick. The manufacturer’s roller guidance says a roller encourages owners to use the cover properly, easily and conveniently. Without one, a removed cover must be stored in full shade every time it comes off.

How long should a pool cover stay on? For heat and water savings, leave it on whenever nobody is swimming, including overnight, when there is no sun to replace the heat the water gives off. Take it off:

• before anyone swims, with the whole cover fully off the water;
• when the water is warmer than you want, or the air temperature passes 35°C, according to the manufacturer’s advice;
• when you shock dose or add a large chemical dose (see the next section);
• before a storm if the water level is high or the cover edge is lifting.

Fit the cover bubble side down, flat side up. A cover does not have to reach every corner to heat the pool, though an uncovered step edge lets debris in and gives wind something to catch. The same maker says suction, pressure and robotic cleaners can run under its covers; check your own cover maker’s advice and see the robotic vs suction cleaner guide.

Pool chemistry with a cover on: what to change

With a cover on, you need to test more often and add less chlorine, because less chlorine escapes to the air and readings climb. The cover manufacturer explains that much of the chlorine that would normally gas off stays in the covered water, so the pool will test higher. High chlorine under a hot cover is also the condition that damages covers most; the manufacturer advises keeping chlorine no higher than 3 ppm for cover life. Your target ranges for chlorine and pH are in the pool chlorine and pH guide.

An owner-safe chemistry checklist for a covered pool:

1. Test the water regularly, and again after hot spells or heavy rain.
2. Turn a salt chlorinator’s output down, or dose less by hand, to match the test result. Follow the product label for any dose; do not guess.
3. Remove the cover completely for a shock dose and leave it off until chlorine reads normal again, as Sunlover Heating’s pool blanket care guide advises. Daisy Pool Covers also advises shock chlorinating before fitting a new cover and letting chlorine return to normal, because chloramine gas can build up under a cover and create high pressure.
4. Run the filter through the hot middle of the day, which mixes warm surface water down and stops chlorine building up under the cover, according to Daisy Pool Covers.
5. Keep an eye on algae. Warm water, low chlorine and phosphates feed algae with or without a cover. If the pool turns, use the green pool guide.

Chemical handling has a clear boundary. Hazardous pool chemicals come with a label and a Safety Data Sheet (SDS), which Safe Work Australia says carries important safety information. Read both before use, never mix products, and ask at a pool shop if a dose or reading is unclear. For products and advice, see our pool chemical supplies page.

Safety: why a pool cover is not a pool fence

A pool cover is not a pool fence and cannot replace one in Queensland: the Queensland Government states that if you have a pool, it must have a pool fence or barrier. That barrier must comply with Queensland Development Code MP 3.4, which calls up and modifies Australian Standard AS 1926 (2007), and it must be at least 1200mm high above ground level. The government also states that spas and some portable wading pools need a complying barrier even if they have fully lockable, solid covers. If a solid lockable lid does not remove the barrier requirement, a floating solar blanket does not either.

The stakes are high. The Queensland Government says drowning is one of the leading causes of death in Queensland for children aged under 5, and that supervising young children, teaching them to swim at a young age and effective pool fencing can save lives. Treat a covered pool as an open pool and keep supervising children.

Two owner checks that relate directly to covers: Queensland guidance says to remove climbable objects within 900mm of the pool barrier and secure moveable objects near the pool, so do not park a roller, stored cover or storage box where a child could use it to climb the fence. And never prop a gate open while you handle the cover. For fence compliance questions, contact a licensed pool safety inspector or your local council.

Caring for a cover so it lasts, and when to get help

A cover lasts longest when it is kept out of the sun while off the pool, used with chlorine in range, and cleaned gently, which is what decides whether it stays worth the outlay. The manufacturer says every cover has a finite lifespan and that care ultimately determines how long it lasts, and that chlorine and UV constantly attack a solar cover, with both effects magnified by high Australian summer temperatures. Some makers, such as Daisy, use pro-rata warranties, so check the terms for your cover and what care they require.

Owner-safe care checklist:

• Store the cover on a roller under its over-cover, or fully in the shade. The maker’s storage advice warns that shade cloth or a patio is not enough, and that a folded or rolled cover left in sun can overheat and shrink, shortening its life.
• Rinse off leaves and dust; sweep or hose debris towards the skimmer rather than dragging it into the pool.
• Keep chlorine in range and run the pump in the heat of the day.
• Check the edges after heavy rain and lower the water level if the cover rides above the coping.
• Inspect the cover each season for wear or damage.

Know where to stop. A hard-wired automatic cover and any fixed pool wiring must be installed and maintained by a licensed electrician, as Queensland’s Electrical Safety Office requires for pool wiring and electrical equipment. For a battery or plug-in roller, follow the maker’s instructions and plug it in only through a safety switch, as the Electrical Safety Office advises for any electrical equipment around water. Owners can check that the safety switch is on and keep the drive dry, but must not open, rewire or extend power to it. Barrier compliance belongs with a licensed pool safety inspector. For cover and roller options, see our pool covers page or contact Billabong Pool Service.