Two girls splashing. Source: iStock
One of the most frustrating things about having a pool is watching water levels drop – sometimes in just a few hours. This can lead to frequent top-ups, which can increase water and chemical bills, not to mention deplete one of our most precious resources. Luckily, pool water loss can be minimised or even prevented if you understand why it happens. Here are five reasons why your backyard pool is losing water:
Evaporation is one of the main reasons why pools lose water. That’s because conditions like strong wind, heat and humidity turn water into vapour. As a result, you can lose about 7 millimetres of water a day in summer – or more if your pool has a large surface area, gets a lot of sun exposure or is positioned in a windy area. What’s more, if you live in a region with high temperatures and low humidity, it can make evaporation worse. See the table below for daily evaporation rates for a 9.2 x 4.5 m pool.
Mean Daily Evaporation Rate Table. Source: Daisy Pool Covers Factsheet 1 – Evaporation
While a certain amount of pool evaporation is normal, too much can affect how your pool works. For example, if water levels drop below the halfway mark of your skimmer recess, it can prevent water from circulating. This can make your pool cloudy and even damage your pool pump (if your pool pump sucks air instead of water, it can burn out). What’s more, excessive evaporation can unbalance your water chemistry. Not only does this allow bacteria and algae to multiply, but it can also corrode your pool surface and equipment, reducing their longevity.
If you’ve got a media filter, your filter needs to be backwashed regularly to remove debris. This means flushing it with water for two or more minutes at a time. If you backwash every week in summer, you could be losing up to 5,000 litres of water a year. Not only does this lower your water levels, but it also unbalances your pool chemistry, resulting in higher water and chemical bills.
Pool leaks are more common than you think. They can be due to loose fittings, gaps around your pool lights or cracks/tears in the pool structure. The amount of water you lose will depend on the type of leak and its severity.
To test for a leak, use the bucket test. This involves placing a bucket on your pool step and filling it to match the pool’s water level. Wait 24–48 hours and see if the water level in the pool has dropped (don’t use the pool or backwash function during this time). If it has, you’re likely to have a pool leak.
To find it, check for wet areas around your pool pump, filter, heater and salt chlorinator, or examine the pool surface for tears, cracks or loose light fittings. If you can’t identify the problem, there may be a plumbing problem you can’t see. In that case, contact a pool technician for a full inspection of your pool.
While everyone loves splashing, dive-bombing or squirting water guns in the pool, these activities can cause water loss or overflow, particularly if you don’t have a perimeter drain around your pool. What’s more, if swimmers get in the pool with their clothes on or your four-legged friends go for a paddle, they’ll absorb more pool water than usual, reducing your pool water levels further.
If you’re using a manual vacuum to remove leaves from your pool or particles after using a flocculant, your pool could be losing hundreds of litres of water per year. That’s because vacuuming to waste removes debris and water. If vacuuming is done quickly, water loss may be minimal, but if you vacuum regularly, it can reduce your water levels, resulting in frequent top-ups and eye-popping water bills.
If your pool has been losing water, it’s not too late to turn things around. Here are some expert tips to reduce water loss in your pool:
Pool covers don’t just protect your pool from environmental debris. They can also reduce water evaporation by 90–95 per cent, saving you 3,000 litres of water each month. But if you can’t find the right size for your free-form pool or you don’t like the aesthetic of pool covers, the next best thing is a shade sail. Not only does it reduce evaporation and chlorine depletion (as long as it’s UV-resistant), but it’s also a permanent structure that provides much-needed shade for swimmers.
Pool cover. Source: iStock
If your pool has a media filter, consider switching to an eco-friendly cartridge filter. It won’t require backwashing, which can waste thousands of litres of water each year. Instead, you just remove the filter from the housing and rinse it with a hose. If it’s really dirty, you can soak it in a filter cleaning solution, which uses even less water. If you don’t want to upgrade your media filter, switch from sand to glass filter media. Glass media is smooth and loosely packed, allowing for faster and less frequent backwashing.
If you’ve identified a pool leak, don’t let it get worse. Tighten any loose fittings on pool equipment and patch any cracks or holes. Luckily, many fibreglass or vinyl-liner patch kits can be used underwater, so you won’t need to drain your pool. For more information, see our guide on how to repair a leak. If the leak persists, contact a pool technician or leak detection specialist for a full inspection of your pool.
Have you noticed how water evaporates quicker when it’s heated? That’s because heat makes water molecules move faster and escape as gas or vapour. This process speeds up when there’s a large difference between the water temperature and the air temperature – and why a heated pool evaporates faster at night than it does during the day. To counteract this, reduce the temperature on your thermostat, avoid heating your pool at night or close your pool for winter.
While pool features add style and ambience to your pool area, they can also increase water loss. As the water sprays or cascades, each droplet is exposed to air and heat, causing evaporation. To reduce this, put your water features on a timer so they only run for short periods of time, and turn them off if heavy wind is diverting the spray away from your pool. Alternatively, choose water features that minimise evaporation. For example, rockeries with trickling waterfalls won’t evaporate as much as fountains or deck jets.
If you find it difficult to minimise splashing, consider installing a perimeter drain to capture and recirculate water from your pool. This is often installed in the pool coping or deck. While perimeter drains can be expensive to retrofit (and may disrupt your landscaping), they can save you thousands in water bills further down the track. As a bonus, they capture water runoff that might contaminate your pool and provide a slip-free surface for swimmers.
White pool grating. Source: iStock
When your pool is exposed to windy conditions, water can get blown out of your pool or evaporate quickly. The best way to counteract this is with a windbreak. This can take the form of a fence, wall or hedge. In general, artificial barriers are easy to install and provide more wind protection than hedges. What’s more, you don’t have to wait for them to grow!
Not only does running a pool cleaner keep your pool healthy and swim-ready, but it also reduces water loss. That’s because debris such as leaves, soil, sunscreen and hair can clog your filter, resulting in frequent backwashing or rinsing. This can waste thousands of litres of water each year – and ramp up your water bills. By running your automatic pool cleaner regularly, you’ll pick up excess debris from your pool before it reaches your filtration system. Not only does this increase the longevity of your filter, but it also reduces the frequency of your rinsing/backwashing cycle.
It’s not unusual for pools can lose thousands of litres of water each year due to evaporation, backwashing, leaks, splashing or vacuuming. Not only does this increase pool running costs, but it can also deplete our natural water resources (particularly if you live in a drought-prone environment). While pool water loss can’t be avoided, here’s what you can do to minimise it:
By implementing one or all of these strategies, you can reduce top-ups, cut down on water bills and make pool maintenance easier. Want more tips on how to reduce energy and water consumption in your pool? Then check out our video on eco-friendly pool tips or chat to one of our stockists for expert advice.