Pool Evaporation vs. a Leak
Every Florida pool loses water. The question is whether yours is losing more than the weather explains — and there is a simple test that answers it.
Why Evaporation Varies So Much
Evaporation depends on water temperature, air temperature, humidity, wind exposure and surface agitation. A heated pool with a waterfall in an open, breezy yard loses far more than a screened, shaded pool at the same time of year. Splash-out from swimmers and backwashing the filter also remove water without any leak.
That is why fixed rules of thumb about inches per week are unreliable. A comparison test controls for the weather because both bodies of water experience it.
The Bucket Comparison Test
- 1
Set up
Place a bucket on a pool step so it is partly submerged, and fill it with pool water so the inside and outside levels match.
- 2
Mark both levels
Use tape to mark the water level inside the bucket and on the outside of it.
- 3
Leave it undisturbed
Turn off any auto-fill, avoid swimming, and let a full day pass with normal equipment operation.
- 4
Compare
Levels dropping equally suggests evaporation. The pool dropping noticeably more suggests a leak, and the difference indicates its scale.
Pump On or Pump Off
- Faster loss with the pump running suggests pressure-side plumbing or return lines
- Loss that continues with the pump off suggests the shell, skimmer, light niche or main drain area
- Air drawn into the system or loss of prime suggests a suction-side issue
- A level that falls then stabilizes at a fitting or tile line narrows the elevation of the leak
Do Not Forget the Auto-Fill
An automatic fill valve masks a leak entirely by replacing the lost water. The pool looks fine and the water bill quietly rises. Any water-loss investigation should start by disabling it so the pool can tell you the truth.
Not sure where the water is coming from?
Describe what you are seeing and we can explain how the investigation would be approached on your property.
Frequently Asked Questions
- How much water loss is normal for a Tampa pool?
- It varies with weather, sun, wind and whether you heat the pool or run water features. Rather than a fixed figure, compare your pool against a reference container under the same conditions.
Related Pages
If you are still narrowing things down, start with Tampa leak detection.