Pool losing water
Why is my pool losing an inch of water a day?
A pool losing a full inch a day in the Phoenix valley is losing more water than the weather can account for in any month of the year, which means it is almost certainly leaking through the plumbing, the shell or a fitting. Evaporation here is real and it is large, but it is not that large.
What it usually is
An inch a day is past what the sun can take
A pool dropping an inch a day usually means water is leaving through a pipe, a crack or a fitting rather than through the surface.
Scottsdale Water publishes month-by-month evaporation figures for an open pool in this climate, and even June works out to roughly a third of an inch a day. An inch is several times that, in the worst week of the year.
The other tell is steadiness. Evaporation follows the weather, so a pool that is only evaporating loses less on a humid monsoon morning than on a windy May afternoon. A leak does not care what the sky is doing.
Be honest about it
What it could be instead
Rule out the things that move a pool level fast with nothing wrong:
- The auto-fill has just been closed. The pool was losing water all along and the valve was hiding it.
- A busy weekend, or a water feature on a windy day. Both carry water out of the pool for honest reasons.
- Backwashing, or draining after a storm. A visible amount at once, easy to forget a week later.
None of those repeat for a fortnight. If the drop does, the leak list starts.
Narrowing it down
What the pattern of the drop tells you
| What you are seeing | What it points at | What to check first |
|---|---|---|
| Same drop whether the pump runs or not | The shell and its fittings | Tile line, skimmer mouth and light niche, in daylight |
| Worse while the equipment is running | The pressure side of the plumbing | How much worse, in inches, then a day with the pump off |
| Falls, then stops at one height | A fault at that height | Mark where it settles, and leave the mark |
Ten minutes, on your own
Four things worth doing before anybody drives out
None of it needs a tool you do not own, and all of it makes the visit shorter.
Close the auto-fill
It replaces exactly the water you are trying to measure.
Mark the water line, with the time beside it
A grease pencil mark and an hour written next to it beats any description.
Look along the tile line and into the skimmer
Missing grout, a hairline crack below the tile, or a gap at the skimmer throat show up in good light.
Then run the bucket test properly
It is the only check that separates weather from leak. The method is on our bucket test page.
How urgent is it
Urgent for the equipment, rarely for the house
A pool losing water is not flooding anything, so this is almost never a middle-of-the-night problem. Two things change that.
- The level nearing the bottom of the skimmer mouth. Below it the pump draws air, which is hard on the equipment. Switch it off.
- Saturated ground against the house. A buried pool line losing water beside a footing has stopped being a pool problem.
If you call us
What we actually do with a pool that drops like this
Every line is isolated and pressure tested on its own, suction and returns and the cleaner line separately, because testing them together tells nobody which one failed. Where a line will not hold, we listen for it acoustically and trace the run, so the loss ends up with an address rather than a general area.
Where every line holds, attention moves to the shell: dye at the fittings, the light niche and any crack the tile line has hidden. You are shown the spot before anything is opened. See pool and spa leak detection.
Straight answers
Pool water-loss questions
Is losing an inch of water a day normal for a pool in Phoenix?
No. Scottsdale Water's published evaporation figures for an open pool in this climate work out to roughly a third of an inch a day in June, the worst month of the year. An inch a day is several times what the weather can take.
Could my pool lose an inch a day and still not be leaking?
For a day or two, yes. A party, a windy afternoon with a water feature running, or a filter backwash each take a visible amount at once. None of them repeats every day.
Should I keep running the pump while the pool is losing water?
Run it normally unless the level is nearing the bottom of the skimmer mouth. Below that the pump draws air instead of water, so switch it off and top the pool up by hand.
Does the pool have to be drained to find the leak?
No. Pressure testing, acoustic listening and dye tracing are all done with the pool full, and an empty shell in Valley soil carries risks not worth taking for a diagnosis.
Pools we work on across the Valley
Tell us what the water is doing
Your mark on the tile, the hours between readings, and whether it was worse with the pump on or off.
Send us the two measurements
How far it dropped, over how long, and whether the equipment was running.
5.0 on Google
What customers in the Phoenix valley have written. The words are theirs, on listings we cannot edit.
“Humberto has been amazing! Prompt, professional, and patient. He has gone above and beyond, taking the time to show me how to operate the water valves and educating me so I can continue to monitor for future leaks. He identified multiple leaks and made thoughtful recommendations.”
“Beto was very professional, thorough and patient in explaining everything he was doing and why. It was an excellent and well worth it experience, and this is saying something for an architect who had a hundred questions!”
“The owner and operator of this company is everything a contractor should be. On time, honest, competent, reachable, comprehensive. Hope to work with him again in the future.”