Why is my pool losing water? Leak or Evaporation?
If you’ve noticed your pool water level dropping, you’re not alone — it’s one of the most common concerns we hear at Flow Pool Services.
But the big question is:
Is your pool leaking, or is it just normal evaporation?
Understanding the difference is crucial to protecting your pool, preventing damage, and avoiding costly repairs. In this blog, we’ll explain how to tell if your pool is leaking or evaporating, and what steps you should take next.
How Much Water Loss Is Normal?
Some water loss is completely normal — especially during hot, sunny, or windy weather.
Typically, your pool can lose:
- ¼ inch to ½ inch of water per day through evaporation.
- Up to 2 inches per week depending on your climate and pool conditions.
If your water loss falls within this range and matches periods of high heat, evaporation is likely the cause.
Common Causes of Evaporation
Several factors can speed up evaporation, including:
High Temperatures: Hot weather accelerates water loss.
Low Humidity: Dry air pulls moisture from the pool surface.
Wind: Wind blows away the water vapor as it forms.
Pool Heating: Heated pools lose water faster due to the temperature difference.
Tip: Using a pool cover dramatically reduces evaporation and can save thousands of gallons of water every year!
How do I know whether my pool has a leak?
If your pool is losing more than ½ inch of water per day, evaporation might not be the only issue.
Here are signs you might have a leak:
- Wet spots or soggy ground around the pool
- Cracks in the pool deck or pool shell
- Air bubbles in the return lines
- Consistently low water levels even after topping off
- Higher water bills without increased usage elsewhere
Leaks can occur in the pool structure, plumbing, or equipment — and the longer you wait, the worse (and more expensive) they become.
How to Tell the Difference: The Bucket Test
At Flow Pool Services, we often recommend the simple bucket test to help determine whether you have a leak:
- Fill a bucket with pool water about 3 inches from the top.
- Place the bucket on a pool step (weighted down if necessary) so the water inside the bucket and the pool water are at the same level.
- Mark the water level inside the bucket and the pool level outside the bucket.
- Wait 24–48 hours without using the pool.
Compare the two water levels:
If the pool water level has dropped more than the bucket water, you likely have a leak.
If they have dropped the same amount, it’s probably just evaporation.
What to Do If You Suspect a Leak
If you think your pool has a leak, it’s important to act quickly:
- Turn off unnecessary water features and check equipment for obvious leaks.
- Contact a professional leak detection service to accurately locate and fix the problem.
- Avoid DIY leak repairs unless you are 100% sure — improper repairs can worsen the issue.
Trust Flow Pool Services to Help
Whether it’s evaporation or a real leak, Flow Pool Services is here to help you protect your pool investment.
We offer affordable month-to-month maintenance — with no contracts required!
