Everything You Need to Know About Evaporation

When your pool is losing water, it’s natural to be concerned. The good news is that water loss is most likely due to natural evaporation, which occurs in every pool.

What causes evaporation?

Temperature: The difference between the temperature of the pool’s water and the temperature of the outside air is what causes evaporation. Because of this, you will lose more water to evaporation in the spring and fall, when the water temperature fluctuates from warm to cool during the course of a day, than in the summer, when the temperature is more consistent throughout the day.

Lack of humidity: The drier the heat, the more water from your pool will be absorbed. This is good news for North Carolinians! Our humid summers help to reduce the amount of evaporation your pool experiences.

Exposure to elements: The more sun and wind your pool is exposed to, the more water it will end up losing. If your pool area is well shaded by trees or a fence, you will probably not notice as much evaporation as someone with a pool that has no shade covering.

How can evaporation be prevented?

One of the most effective ways to prevent evaporation is to use a solar blanket to cover your pool when it is not in use. Solar blankets are great for retaining heat and preventing heat loss, and as an added bonus, they can protect your pool against the biggest factors contributing to evaporation, listed above. A standard pool cover will also help to slow down the rate of evaporation.

What is a normal amount of evaporation?

On average, pools can lose about a quarter inch of water each day due to evaporation. If you feel that your pool may be losing more than that, you can perform a simple test to track the rate of evaporation, using a bucket and a permanent marker.

  • Place an empty bucket on the first or second step of pool, ensuring that it is sitting in at least five inches of water.
  • Fill the bucket with enough water that it exactly matches the water level outside of the bucket.
  • Mark the water level on the inside of the bucket and the pool water level on the outside of the bucket using a permanent marker.
  • After at least 24 hours, compare the two water levels. If the the levels are the same, normal evaporation has occurred. If the pool water level has decreased more than the water in the bucket, you may have a leak in your pool, and you should contact us immediately so we can begin repairs.