ABC Blog

What Is My Pool’s Evaporation Rate?

a pool with low water levels which leads a homeowner to wonder what their pool evaporation rate is

Pools generally lose about a quarter of an inch of water every day due to evaporation. That said, the evaporation rate depends on several circumstances in your local environment. This means that even under typical conditions, your pool could lose thousands of gallons of water each year from evaporation.

The easiest thing to do is check an evaporation rate map for your area, such as the one made by the National Weather Service. However, if you want to estimate the specific evaporation rate in your pool, you can also measure it.

Using a tape measure or ruler, measure the distance between the surface of your pool water and the top of the pool deck. Wait a week to let the water evaporate and then measure this same distance between the water and pool deck again.

Subtract the first measurement from this second measurement to get a value for how much the water level has changed. This number can give you a simple estimation of how fast your pool water is evaporating. If the water level has changed more than about a quarter inch each day, then your pool might be having problems.

To get the evaporation rate, you’ll need to do a few more calculations. If the measurement for the change in water level is in inches, divide it by 12 to convert it to feet. Then, multiply this number by 7.48 and then by the surface area of the pool. This will give you the value for the number of gallons of water that you lost.

Next, divide this value by the number of days that have passed. For example, if you waited exactly a week between the first time you measured the water level and the second time, then you’ll want to divide the value of gallons of water lost by 7. This calculation will give you a general estimate for your pool’s evaporation rate in gallons per day.

However, it’s important to remember that several events could mess up your calculations and make it hard to get an accurate measurement. For example, if you add water to the pool during the week or if it rains. Some examples of other factors that could speed up water loss or increase your pool’s normal evaporation rate include the following.

Temperatures Over 100 Degrees or Unusually Cold Temperatures

The scientific process of evaporation occurs when the temperature of the water is different than the surrounding air. This is why evaporation can occur when it gets very cold outside, especially if you heat up your pool or spa.

Additionally, if you live in an area where the days are very hot and it’s much cooler at night, this could also lead to higher evaporation rates. The pool water typically retains some cool overnight temperatures, which means that during the day, there can be a large difference in temperature between the water and air. The evaporation process speeds up when this cool water comes into contact with very hot air.

Direct Sunlight on the Pool

Similar to what happens when temperatures rise above 100 degrees, evaporation also speeds up if there’s sunlight shining on your pool. If you don’t keep a cover over your pool or have trees that shade the pool, the evaporation rate can increase, even on days that you don’t use the pool.

A Lack of Humidity

If you live in an area that always has low humidity or if your area is experiencing unusually low humidity, it’s likely that the air will more quickly absorb water from your pool. A good analogy for humidity in the air is a sponge. If the air or sponge is already wet, then it won’t soak up much more water. However, if the air or sponge is dry, then it’s more likely to suck up any water it finds.

Using the Pool

Whenever you use the pool, there is a chance that water will splash out. Even if you’re gently stepping into and out of a pool, water will stick to your body as you leave. The pool loses water even more quickly when you, your friends or your family jump into the pool or play in the water and splash around.

Water features in your pool can also contribute to water loss. For example, features like jets and waterfalls can cause water to splash out. Plus, these features generally expose the water to air and can increase the evaporation rate.

High Winds or Severe Weather

Similar to what happens when you use your swimming pool, environmental factors can also speed up water loss. For example, high winds can blow water out of your pool or large hail can cause water to splash out of your pool. Severe weather may also lead to cloudy pool water.

While some evaporation is normal, you might also be losing water from your pool because of a leak. The best way to figure out whether you have a pool leak is to call a professional as soon as you think you might have pool problems.

If you try to fix the problem on your own before contacting a pool care specialist, then the issue could get worse and turn into a much more costly problem. However, when you hire an expert, they can help make sure the problem gets fixed. This way, you and your family members can go back to enjoying your pool in no time.

a concrete swimming pool and two lounge chairs

How to Find a Leak in a Pool

There are several signs that you can look out for to determine if your pool might have a leak. The most common sign is if your pool is losing water. However, it’s important to keep in mind that it is normal for pools to lose some water. Water loss on its own isn’t necessarily a sign of trouble unless your pool is losing more water than usual.

One way you check if your pool might have a leak is by using the bucket test. To do this test, fill your pool with water and then also fill up a bucket until the water level is about an inch from the top. Put the bucket on one of the top steps in your pool. Then, use a marker or piece of tape to mark the water level inside the bucket. Do the same for the level that the pool water reaches on the outside of the bucket.

Leave the bucket there for about 24 hours. After this time has passed, check the water levels inside the bucket and the level of pool water surrounding the bucket. If the pool water level has dropped much further than the water inside the bucket, then you might have a leak.

Another common sign that your pool might have a leak is if you start to notice water around your pool equipment or moist spots in your yard. Make sure to check in the area around your pool or in spots between your pool and the pool equipment. Additionally, if your water bills start to rise for no obvious reason, then you might have a pool leak. Broken concrete around your pool or cracked tiles inside your pool could be another sign of a leak. Also, a chemical imbalance in your pool water could be a sign of trouble.

If you would like to try to look for a leak on your own, the simplest way is to do a visual spot check. You might be able to spot the leak if you get in the pool and look for tears or cracks in the pool’s surface or see water flowing in an unusual direction. Another common method is to squirt colored dye near the suspected leak. If there’s a leak, then the colored liquid will likely get sucked into the hole. Lastly, if your pool pump won’t prime, there’s a chance there’s a leak somewhere.

However, if you suspect you might have a pool leak, it’s best to contact a pool professional right away. They can find and fix the issue as soon as possible. The sources of leaks are often difficult to find without proper training or tools. When homeowners try to locate leaks on their own, it can often take a lot of time. Meanwhile, the leak can get bigger and create even more complicated issues.

a cloudy pool

Pool Pump Leaking at Housing

A common reason that a leak might develop on a pool pump at the housing is if parts like the o-ring seal start to wear down. Or, if the bolts, pump drain plug or clamp come loose. Leaks can also develop if you have a major freeze in your area that damages the pool pump.

If you suspect you have a pool leak, the best way to get the problem resolved is to contact a professional. They will inspect the pump housing and other areas of the pool and might run tests to figure out where the problem is. If they determine that the pump housing is the source of the leak, then they will likely replace broken or worn-out parts of the housing. Then, they will make sure all the connections are secure. They can also answer any questions you may have about how long pool pumps last.

ABC Can Find and Fix Any Pool Leaks

The best way to deal with any pool problem is to contact a certified professional. When you contact ABC Home & Commercial Services, you can have peace of mind that our professionals will diagnose your problem quickly. Then, we will present you with a plan of action, so you don’t have to worry about any more leaking equipment. Additionally, we offer ongoing pool maintenance which allows us to catch small problems before they turn into more costly headaches. We can even help with closing your pool for the season.

Learn More