Pool owners often experience problems with water evaporation. Not only can this increase operating costs for pools, but it can also negatively impact the environment, especially where water is scarce. Thus, pool owners must find ways to minimize water evaporation so as to protect both the environment and their wallets.

Throughout this article, we will examine the causes of pool water evaporation and present several solutions for reducing it. 

Pool water evaporation: what's the cause?

Evaporation is the natural process by which a liquid turns into a gas, usually as a result of heat. There are several factors that can contribute to the speeding up of this process in a swimming pool:

Water temperature and air temperature

A higher water temperature and a lower air temperature lead to an increased evaporation. The pool is like a glass of water left on a table; as it heats up, it forms steam, which evaporates.

The wind

Wind blowing across a water surface increases evaporation by displacing warm, moist air that accumulates above it. Likewise, what is true in nature also applies to swimming pools.

Air humidity

During periods of low air humidity, water evaporates more rapidly in an effort to maintain an acceptable concentration of water vapor in the air.

Which causes pool water loss: leaks or evaporation?

Due to changes in humidity and temperature, pools normally lose some water, but they should not lose more than a quarter inch of water per day.A significant drop in water level that cannot be explained by evaporation or overflow from pool use indicates that your pool may be leaking.

There are several factors that can contribute to a leak in a swimming pool, including damage to the pool structure, problems with the plumbing system, or worn seals. Do a bucket test if you suspect a leak: take a bucket and something to weigh it down. Put it on the first step of your pool and fill it with water to the same level as your pool. Mark the level on the bucket with an indelible pen and wait 24 to 48 hours before checking it. When the bucket level is higher than the level in the pool, you can be certain there is a leak. We recommend that you hire a professional to inspect and repair your pool. It is important to note that a leak does not only result in water loss, but may also cause structural damage to your pool and property.

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    Is it possible to calculate the pool water evaporation rate?

    Knowing the amount of water loss can help you make an informed decision about your pool maintenance, allowing you to conserve water and reduce energy costs. Easy way to estimate pool water evaporation:

    1. Fill your pool to its normal level. 

    2. Mark the water level on the pool wall or measure the distance between the bottom edge of the coping and the water.

    3. Do not use the pool for a period of time, such as overnight. During this time, do not add water to the pool.

    4. Measure the water level again after this period and note the difference between the initial measurement and the current measurement.

    5. This difference in water level indicates the amount of water lost through evaporation and perhaps leaks.

    6. When the difference exceeds 0.4 inches (ca. 1 cm), a bucket test, see above, must be conducted to confirm leaks.

    This test is more accurate if no rain has fallen during the testing period and the pool has not been used. Furthermore, evaporation varies with climate, water temperature, wind exposure, and humidity.

    Pool water evaporation: what are the consequences?

    On the economic front, evaporation increases water consumption, which results in higher water bills. Furthermore, the pump may burn out if the water level falls below the skimmers and the pool is not filled manually or automatically.

    A significant environmental impact of evaporation is the excessive use of water, especially in regions with a limited supply of water. Furthermore, the chemicals used to treat pool water can evaporate along with the water and disperse into the atmosphere, contributing to air pollution.

    Here are some tips for reducing pool water evaporation

    Now that you are aware of how water evaporation from a pool occurs, let us move on to tips for preventing water waste

    Consider using a pool cover

    One of the most effective ways of decreasing pool water evaporation is to add a pool cover. A pool cover acts as a barrier between the pool and the air, preventing evaporation. It also helps to keep the pool clean by preventing dirt and debris from entering the pool. In addition, a pool cover can help maintain the water temperature, which reduces heating costs.

    From solar covers that use the sun’s energy to heat the water, to robust safety covers that can also prevent access, there are many types of pool covers available.

    Covers for swimming pools typically include :

    • Bubble blankets : These covers are essential for maintaining a comfortable water temperature and reducing evaporation during the swimming season.
    • Safety covers with rods : These covers are stronger than bubble covers and are often used for safety and to reduce evaporation. There are cross rods that keep them in place and prevent access to the swimming pool.
    • Slatted covers : Slatted covers can be rolled up or down manually or automatically. Underwater and above-ground versions are available. The covers provide additional security, similar to bar covers. Typically, they are an attractive option for infinity pools.
    • Winter pool covers : These covers are designed to withstand winter weather conditions and protect your pool when it is not in use. They are typically made of heavy and opaque materials, which minimize evaporation and prevent algae growth.

    Install a pool enclosure

    A pool enclosure is another excellent way to minimize evaporation. It provides protection against the elements as well as an enclosed environment that limits water evaporation. As an additional advantage of pool enclosures, they allow you to extend your swimming season by maintaining a higher water temperature.

    Control water temperature

    Evaporation may also be reduced by maintaining a moderate water temperature in the pool. Evaporation is accelerated by higher water temperatures. Consequently, it may be advisable not to turn up the thermostat too high if you heat your pool. It is recommended to maintain an average temperature of 78 degrees Fahrenheit (ca. 26 °C), and a maximum temperature of 82 degrees Fahrenheit (ca. 28 °C).

    Minimize wind exposure

    Pool water can evaporate more rapidly due to wind, as we discussed above. If your pool is located in a particularly windy area, you may wish to consider installing barriers to limit wind exposure. Planting trees or hedges, as well as installing protective fencing or screens, are examples of this type of project.



    Evaporation of pool water is both an economic and an environmental concern in 2023. If you understand the factors that contribute to evaporation and implement the solutions above, you will be able to conserve more water in your pool. The benefits of this approach include saving money as well as preserving a valuable resource.

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