If you’ve noticed your pool losing water, you’re probably asking the same question we hear all the time: “Is this normal for evaporation, or do I have a leak?” The reality is, most pools will lose some water, but in many cases, what homeowners assume is normal evaporation turns out to be an active leak. Check out our pool leak detection services to learn more about our process.
Below are the most common signs we see in the field, and how to tell when it’s time to take the next step.
Quick Signs Your Pool May Have a Leak
There are a few common patterns that often point to a leak. If you find yourself adding water every few days, noticing water loss that exceeds normal levels, or dealing with a pump that struggles to stay primed with air in the system, it may indicate a problem. Other signs can include air bubbles coming through the return lines, wet or soft areas forming around the pool, or the water level consistently dropping to a certain point and then stopping. If you’re seeing one or more of these conditions, there’s a strong chance your pool may be leaking.
How Much Water Loss Is Normal?
Most pools can lose water due to evaporation, but there’s a range that’s considered normal (learn how to determine if a pool leak or evaporation is the cause).
In most cases:
- 1/8” to 1/4” per day may be normal (1–2” per week)
- 1/2” per day or more is on the higher end depending on weather conditions
Heat, sun exposure, and wind can all increase evaporation. However, if your pool is consistently losing more than 2-3” per week, it’s probably not evaporation, and likely a leak.
Common Signs Your Pool May Have a Leak
Constantly Adding Water
If you find yourself regularly topping off your pool, it’s one of the clearest signs your pool has a leak. Most homeowners assume (or convince themselves) that it’s evaporation, but we routinely see pools losing water for weeks or even months before the issue is addressed.
Air Bubbles or Pump Losing Prime
Air bubbles coming through the return lines or a pump that struggles to stay primed often indicate a suction-side plumbing issue. This typically means air is being pulled into the system, which can point to a break or leak in underground piping.
Increased Chemical Usage
If your pool suddenly requires more chlorine, or you find yourself adding salt more frequently in a saltwater pool – and you’re struggling to maintain proper chemical balance, water loss may be the cause. When water leaks out, chemicals leave with it. Fresh water then dilutes the remaining chemicals, making it difficult to maintain consistent levels. We routinely see this as an early sign of a leak that hasn’t yet been identified.
Wet or Soggy Areas Around the Pool
Soft ground, wet spots, or areas that never seem to dry out around the pool or yard can indicate a leak underground. In many cases, this points to broken plumbing lines or leaks near fittings or the pool shell itself.
Cracks in the Pool or Tile
Not all cracks leak, but some do.
Cracks can allow water to escape through the pool shell, tile lines, or expansion joints. Even small cracks can contribute to ongoing water loss over time.
Pool Losing Water to a Certain Level
This is one of the most telling signs of a leak.
If your pool consistently drops to a specific level and then stops, the leak may be located at or near that level. Common areas include skimmers, returns, and pool lights.
Seeing Any of These Signs?
In many cases, these symptoms point to a leak, but the only way to confirm it is through proper testing such as pressure testing.
Learn how we locate leaks using advanced, non-invasive methods on our non-invasive leak detection process page.
Pool Losing Water – Pump On vs Off
A simple way to gather useful information is to compare water loss with the system running and when it is off. You can learn more about this method with our pump on vs pump off test.
Losing more water when the pump is on often points to a pressure-side plumbing leak
Losing more water when the pump is off often points to a suction-side plumbing leak
Losing water at the same rate either way often points to a structural leak source such as:
- Vinyl liner leaks (holes or tears)
- Pool light or light conduit leaks
- Cracks in skimmers or fittings
- Leaks in the pool shell (concrete pools)
While the on/off test isn’t a definitive test, it can help narrow down where the issue may be coming from.
Where These Signs Can Lead
Underground Plumbing Leaks
These are among the most common leaks we find, and one of the most frequently misdiagnosed. Because they are underground, they cannot be visually confirmed and are often missed by companies that rely on visual observation alone.
Identifying these leaks properly requires pressure testing, specialized diagnostic equipment, and years of hands-on experience testing and isolating plumbing lines to accurately pinpoint the source of the leak without unnecessary digging. Learn more about underground pool plumbing leaks.
Vinyl Liner Leaks
Small punctures, holes, tears, or seam separations in vinyl liners can cause steady water loss and are often difficult to detect without the use of electronic testing devices.
Pool Light Leaks
While the light fixture itself can leak, in many cases the issue is not the light, but the conduit behind it, which allows water to escape from the pool and travel beneath the surrounding patio.
We routinely find leaks in this area that have gone unnoticed, allowing water to erode the soil beneath the deck, which can cause sections of the patio to settle or shift.
Skimmers and Fittings
Skimmers, returns, and other wall fittings are common leak points due to movement, age, or seal failure.
When to Call a Professional
These signs are important, but they don’t confirm the exact problem. We routinely see situations where the symptoms point in one direction, but the actual leak is located somewhere else entirely. While leak detection is a science, it’s not always straightforward, so without proper testing and diagnostics, it’s easy to misdiagnose the issue.
Why Proper Leak Detection Matters
Accurate leak detection allows the problem to be fixed correctly the first time. Without it, homeowners often end up repairing the wrong area, wasting money on unnecessary work, or digging without knowing where the issue actually is. Professional leak detection uses pressure testing, electronic listening equipment, and non-invasive methods to pinpoint the exact source of the leak, ensuring the right solution is applied from the start.
Frequently Asked Questions
Can a pool leak come and go?
Some leaks may only occur under certain conditions, such as when the system is running or when the water level reaches a specific point. We routinely see leaks that appear inconsistent but are still active and will get worse over time.
Are underground leaks common?
Yes. Underground plumbing leaks are one of the most common issues we find and cannot be identified through visual inspection alone. Proper pressure testing and diagnostic equipment is required to confirm the leak.
Do I need to drain my pool?
No. Almost every leak detection is performed with the pool filled using non-invasive testing methods.
Can leaks get worse over time?
Yes. Leaks may remain consistent for a short period, but they almost always get worse if they are left unaddressed. Leaks do not fix themselves.
How do I know if my pool is leaking or if it’s evaporation?
The only way to confirm a leak is through proper testing. Signs can point you in the right direction, but testing provides a definitive answer.
Unsure If Your Pool Is Leaking?
If you’re unsure whether your pool is leaking, contact us for help or call 732-333-3304.