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As the air heats up, so does the pool water. When the temperatures in midsummer rise, it quickly becomes as warm as in a bathtub.

Is your pool too warm, and therefore you are googling how to cool down the pool water?

Then you’ve come to the right place.

With the following approaches, you can cool your pool and in this way make swimming in the pool a real refreshment again. But how can you cool a pool?

Well, there are several ways to cool a pool. Below, we will introduce you to the best methods.

The reasons pool water is too warm

Warm pool water is typically caused by one of these three reasons: hot air temperature, a pool cover, or a pool heater. If the problem is related to the cover or heater, the solution is simple. Simply turn off the pool heater or leave the pool cover off.

If the air temperature is high, the situation is different. Pool water temperature is much more difficult to control when it is simply really hot outside. Pool water above 25 degrees Celsius is great for relaxing in winter, but if it’s hot in midsummer anyway, the pool should provide refreshment.

Shallow pools, where you can still stand, and freestanding pools heat up especially quickly. The problem with above ground pools is that the side walls also heat up, and this heat is transferred to the water in the pool. Therefore, the water in these types of pools heats up a lot.

11 ways to cool a pool and keep it cool

Heating pool water is much easier than cooling it. There are several approaches to cooling that are more or less effective. Among the best methods are the following.

Bathing at night or in the morning

Yes, we know. It’s not exactly the optimal solution. But the fact is that overnight the pool is cooled. Pool water is coolest at night until the morning hours.

Even in the height of summer, temperatures rarely stay at 25 degrees Celsius at night. The pool water is cooled accordingly, and a swim is wonderfully refreshing. The only question is who wants to jump into the pool at this time of day.

Partial or complete water exchange

A (partial) pool water replacement is another option. The method works as long as your water source also has cold water. For the most part, local water suppliers draw on the cold groundwater (rather than the warm surface water), which is why the tap water is cool even in the summer.

If you use your own water source, well water is a good choice, as it is typically cold. After filling the pool, be sure to check the water quality with a test strip and rebalance the pool chemistry.

However, the method is quite expensive and a lot of water is wasted.

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Provide shade

Provide shade by planting trees and installing fences or awnings. If much of the pool is in the shade, your pool will heat up much less than if it were in full sun. While this alone won’t keep your pool cool, it does contribute a certain amount.

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Fountain

The easiest and cheapest way to cool down a pool is with a simple water feature. There are several types of fountains and fountains for pools that are simply connected to the hose that flushes the water back into the pool. Other variations such as a separate water circuit with a waterfall are also possible.

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The water that is sprayed into the air evaporates faster and draws the heat out of the pool water. The pool is cooled down as a result. This method uses the same physical principle as the steaming cooling towers on old buildings.

In addition, it’s documented that listening to water sounds has a stress-reducing effect for many people.

The best effect is achieved when the water feature is operated at night. The lower temperatures at night cool the pool even more. With this method, your pool will lose more water to evaporation than without the water feature, but you’ll also get rid of the heat at the same time. Compared to a pool you don’t like to swim in, that bit of extra fill water is probably a small price to pay.

Remove trees and shrubs near the pool

We’re contradicting ourselves a bit here, but in fact many plants and trees near the pool also make the pool heat up faster because the air above the pool is still.

However, the air above the pool should be circulating, not stagnant. Remove shrubs and trees that could be an obstacle to the wind, so it can blow away the stagnant air and keep your pool cool this way.

Use a reversible heat pump

Reversible heat pumps are more expensive to purchase than regular heat pumps. These pumps have the great advantage of having a heating circuit and a cooling circuit that can be used to lower and raise the water temperature at will.

The operation of a heat pump is reflected in your electricity bill, but it is a convenient and effective way to cool the pool water.

Cool down the pool with ice

This method sounds obvious at first, but somehow also like a joke from a comic book. You can really cool down the pool with ice cubes. The only question is how much of it you need.

For the water to cool down appreciably and last for several hours, though, you’d need wheelbarrow loads of ice. The high cost of electricity for freezing and the cost of tap water make ice cube production extremely expensive. Compared to the other methods, the ice cube variety is much less economical.

Another disadvantage of this method is that it throws the pool chemistry out of balance. After adding such masses of ice, you need to test the water quality and possibly readjust it.

Note: The masses of are truly enormous. The Wall Street Journal estimates that it takes nearly 4 tons of ice to cool a 75,000-liter pool by just 5 degrees Celsius.

Use a solar heater

Not only can you heat water with a pool solar heater, but you can cool it just as well. Whenever the air temperature is lower than the water temperature, you can run water through the solar panels to cool it down.

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Just as solar heaters are great at collecting heat, you can also give off heat. Run the pool water through the solar heater at night and bathe in a cooled swimming pool the next day.

Install an awning

The advantage of this shade provider is that you can retract or extend the awning depending on the time of day. If several days the pool water is too warm, installing an awning can make perfect sense.

Particularly exciting are automatic awnings equipped with a frahling sensor that automatically retracts them during rain and storms, while they extend all by themselves when the sun is shining, cooling the house and pool.

Take advantage of rainwater

Rainwater can also help you cool down the pool water. The cold rain mixes with the pool water and cools it in this way.

A heavy rainfall can lower the temperature of the water quite a bit. With a cistern, additional rainwater can be collected and directed into the pool.

The problem with rainwater is the impurities that the rain washes into the pool. Furthermore, normal rain has a low pH of 5.5 to 5.7.

Therefore, the pool chemistry requires constant correction. After heavy rain, you should also shock chlorinate to kill all foreign matter in the pool. Normal chlorine tablets are usually not sufficient here.

This method is not suitable for regular cooling of the pool water, as it does not rain regularly either, and cleaning and rebalancing of the pool water is required after each heavy rainfall.

Use of an atomizer

For outdoor areas there are so-called atomizers, these are connected to a water source and emit a fine mist of water. The principle is similar to a spray gun on an even much finer level.

The atomizers are placed near the pool. The water mists then cools the air and therefore indirectly cools the pool.

If you are right next to the pool in the middle of summer, using an atomizer can be uncomfortable because it increases the humidity, which makes the outside temperature feel much hotter.

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As you can see, there are quite a few different methods for cooling a pool and keeping it cool. Among our favorites are the simple things. Set up a water feature, install a solar heater, and try to keep the pool area cool.

If you’re just building your personal pool paradise, it’s worth investing in a high-quality heat pump that can warm and cool the pool.

With these simple tricks, you can refresh yourself in the pool even in the height of summer without ordering truckloads of ice.

Larry has been a true water rat since childhood. Pure pleasure turned into a passion. That's why he is the first point of contact for friends and acquaintances when it comes to pool-related problems. He is an integral part of the PoolHandbook editorial team.