Why Does My Pool Lose Water Overnight?


Do you need to refill your pool several times throughout the week? If your answer is “yes,” you may need to rule out natural causes of water loss. 

Pool Water Loss

Especially during the summer, it’s normal for Florida pools to lose about a quarter-inch of water due to evaporation, low humidity levels, high winds, backwash, and splash-outs. 

However, water loss due to hot weather and evaporation usually happens during the day. If your pool loses more than a quarter-inch of water overnight, then your pool may have a leak.

You can conduct an overnight bucket test to rule out evaporation and other natural causes of water loss.

In this article, learn about pool water loss and how you can prevent losing pool water overnight.


Please include attribution to https://sarasotapoolleakdetection.com with this graphic.

Prevention of Overnight Pool Water Loss

Causes of Pool Water Loss

There are several causes of pool water loss, and below are just a few of them:

  1. Evaporation: Since the pool is exposed to higher temperatures and direct sunlight during the day, evaporation is the most common cause of pool water loss during the day. A pool can lose up to a quarter-inch of water due to evaporation.

Especially in hot states like Florida and Texas, evaporation rates are higher, and pool owners need to deal with more significant water loss. Due to evaporation, Florida pools can lose as much as 2 inches of water every week. 

If humidity is high, the evaporation rate decreases because the air is already saturated with water. 

  1. Backwash: Pools with filtration systems that have backwash features lose more water. 
  2. High winds: Strong winds at night can disturb pool waters and cause splash out. Windy conditions also counteract humid air and increase the evaporation rate.
  3. Surface exposure: The larger the surface area of your pool, the faster it will evaporate. If you have a vast pool, you can expect it to evaporate faster overnight if you don’t have a pool enclosure.
  4. Leaks: If your pool loses more than a quarter-inch of water overnight, you need to check if water loss is due to pool leaks. Especially if your pool doesn’t have heating, waterfalls, and other special features, a leak is likely the culprit.

Leaks along and around the pool surface, skimmers, filters, plumbing, tiles, pump, and liners increase water loss. 

You may waste hundreds of gallons of water daily due to a leak, which will cause your water bills to climb at an alarming rate.


Why Should I be Concerned about Losing Pool Water Overnight?

Significant water loss in your pool overnight is alarming because you can rule out environmental factors such as high temperature and direct sunlight exposure.

Concerns about Losing Water in Pool Overnight

While your pool may lose water from evaporation overnight, the most likely suspect is a pool leak.

If your pool loses a lot of water, you need to spend more money to replace the water lost daily.

Even worse, if you keep adding water to your pool, you can mess up its chemical balance, which can cause algae growth and calcium scaling.

Failing to address these concerns right away will lead to financial loss. 

If you don’t detect pool leaks in time, you will pay thousands of dollars to replace damaged pool equipment and pool structure.


Overnight Bucket Test to Check for Pool Leaks

As mentioned, there are many possible reasons your pool’s water levels drop. The two most probable causes are evaporation and pool leaks.

To rule out evaporation as the leading cause of pool water loss, you must conduct a simple bucket test overnight.

  1. Turn off the pool pump and filtration system.
  2. Get a 5-gallon bucket on the shallow end of the pool or the pool steps. Fill it with enough water to match the pool’s water level.
  3. Mark the pool water line on the bucket with masking tape or a marker.
  4. Leave the bucket for 24 hours.
  5. Observe the water level in the bucket, which is your pool’s daily evaporation rate.
  6. Compare the water level in the bucket versus the swimming pool. If your pool has a lower waterline, water loss is likely due to leaking.

Most inground pool leaks are found in the return lines, skimmer, main drain, pool liner, fittings, and pool shell.


Water loss prevention

How to Prevent Overnight Loss of Pool Water

If your pool loses water mainly due to evaporation, there are several ways to prevent overnight evaporation:

  • Install a solar cover to protect your pool from evaporation and windy conditions. This will require some manual labor.
  • Add a “liquid pool cover.” This invisible chemical prevents pool water from evaporating. You won’t notice the substance while you’re swimming. However, you must keep adding the liquid at least once a month.

If overnight pool water loss is due to a leak, the only way to solve the issue is to get in touch with a pool leak detection service. Pool technicians can easily detect where the leak is located.

Make sure to look for qualified pool experts in Sarasota that will offer budget-friendly and effective repair services.


Overnight Pool Water Loss? 

There are several reasons why your pool loses water overnight.

It will help to rule out evaporation immediately in case your pool leaks. 

Failure to detect pool leaks will force you to refill your pool often and invest in expensive damage to pool structure equipment. So, it is important to look for professional help.

Call (561) 570-1269 now, and we will schedule a pool repair and renovation company in your area to reach out to you. They will schedule a time convenient for you to stop by and give you a bid on the repairs.

Or you can fill out this form, and we will have the best pool renovation company in your area contact you! 

In case you can not view this video here, please click the link below to view Why Does My Pool Lose Water Overnight? | Nelson Pool Company on my YouTube channel: https://youtu.be/YVVu6gjucKA

Recent Posts