How to Tell If Your Pool Is Leaking (And What It Costs to Find)
Brisbane pools lose water to evaporation every day — but there's a point where it stops being evaporation and starts being a leak. A pool losing 25 mm a day is dumping thousands of litres a week and quietly undermining the ground around it.
Normal Evaporation vs a Real Leak
In Brisbane summer, an uncovered pool typically loses 5–10 mm a day to evaporation, more on hot windy days. Anything consistently above 15 mm a day with no swimmers and no backwashing is a leak until proven otherwise.
The Bucket Test
Fill a bucket with pool water and place it on the second step so the water inside and outside sit at the same level. Mark both levels. Turn the pump off and don't swim for 24 hours. If the pool level drops further than the bucket level, evaporation isn't your problem.
Where Pool Leaks Actually Happen
The usual suspects are skimmer box cracks where the box meets the shell, light niche conduits, failed pipe joints on the suction or return lines, and cracked or perished pool shell fittings. Concrete shell cracks are less common than people assume.
Pump On vs Pump Off
A useful diagnostic: if the pool loses more water with the pump running, the leak is likely on the pressure side (return lines). If it loses more with the pump off, suspect the suction side or the shell.
What Detection Costs
Professional pool leak detection in Brisbane typically runs $350–$700 depending on pool size and access. Pressure-testing the underground lines is usually included. Repair cost varies hugely: a skimmer reseal might be a few hundred, a broken underground return line means excavation.
Why You Shouldn't Wait
Persistent leaks saturate the soil around the shell. In Brisbane's reactive clay that causes ground movement, which can crack paving, damage the shell further and in bad cases affect nearby footings.
Frequently Asked Questions
How much water loss is too much?
Consistently more than about 15 mm per day with the pool unused points to a leak. Confirm with the bucket test before calling anyone.
Can a plumber fix pool leaks?
A licensed plumber handles the pipework side — suction and return lines, fittings and any connection to your property's water supply. Shell and interior surface repairs are a pool builder's specialty.
Will my insurance cover it?
Sometimes the resulting damage is covered even when the leak repair isn't. Photograph everything and check your policy wording.