A pool that loses water is the most common call we get, and the most commonly misdiagnosed. Owners are told to dig, or to reline, when the actual fault is a perished weir seal costing a fraction of either. Here is how professional pool leak detection actually works, and what it should cost you in Cape Town.
How pool leak detection works: the three methods that matter
Proper swimming pool leak detection is a process of elimination, not a guess. We run three techniques in order, cheapest and least invasive first.
Bucket test: is the pool actually leaking?
Before anything else, rule out evaporation. A bucket of pool water on the top step, filled to match the pool level, loses water at the same rate as the pool if evaporation is the only thing happening. If the pool drops faster than the bucket, you have a real leak. In a Cape summer a pool can lose 10mm a day to evaporation and wind alone, which is why this step saves so many unnecessary call-outs.
Dye testing: finding a leak in the pool shell
With the pump off and the water still, dye released next to a suspect crack, light housing or weir throat gets drawn into the fault if water is escaping there. It is simple, visual and conclusive for shell leaks. This is how we find hairline cracks that are invisible when dry.
Pressure testing: finding underground pool pipe leaks
If the shell is sound, the leak is in the plumbing. We isolate each line, pressurise it and watch whether it holds. A line that bleeds down has the fault. This is the step that stops a fifty metre garden becoming a fifty metre trench, because it tells us which pipe and roughly where before a spade touches the lawn.
Signs you need pool leak detection
- Topping up more than about 20mm a week beyond evaporation
- Water loss that is faster when the pump is running, which points to pressure-side pipework
- Water loss that is faster when the pump is off, which points to the shell or suction side
- A permanently damp or unusually green patch in the garden
- Air bubbles from the returns, which means the suction line is drawing air
- Chemical costs climbing because you are constantly diluting with fresh water
What pool leak detection costs in Cape Town
Detection is quoted after we see the pool, because a 6m x 3m fibre pool with one pump is a different job to a 12m pool with a spa, a heat pump and three separate lines. What we will not do is quote a repair before we know the fault. Our full breakdown is on the pool leak detection cost page, and the limits of the home methods are covered in DIY pool leak detection.
When a leak means relining rather than repair
One crack gets repaired. A shell that is crazed with hairline cracks, or fibreglass that is lifting across whole panels, is telling you the surface has reached the end of its life. At that point patching is money spent twice. See what a full reline involves in our 10m x 5m Kuilsriver conversion and the relining timeline.
Pool leak detection: frequently asked questions
How do I find a leak in my pool?
Start with a bucket test to rule out evaporation, then dye test around the weir, lights and any visible cracks with the pump off. If the shell tests clean, the leak is in the plumbing and needs line-by-line pressure testing, which is not a home job.
How much does pool leak detection cost in Cape Town?
It is quoted after an on-site assessment, because pool size, the number of separate lines and access all change the work involved. We quote the detection and the repair separately so you are never paying for a repair we have not yet proven you need.
How much water loss is normal in a swimming pool?
Evaporation alone can take around 10mm a day in a Cape Town summer, more on hot windy weeks. Losing more than roughly 20mm a week beyond that is worth investigating.
Can you detect a pool leak without digging?
Yes. Dye testing and pressure testing identify the fault and narrow it to a specific line before anything is opened. Digging, when it is needed at all, is one targeted excavation rather than a search.
Why is my pool losing water only when the pump is running?
That usually points to the pressure side: the return lines or the filter plumbing, which are only under pressure while the pump runs. Loss with the pump off points instead to the shell or the suction line.
Does a pool leak mean I need to reline the pool?
Not usually. A single crack or a perished seal is a repair. Relining becomes the honest answer when the surface is crazed with cracks or the fibreglass is lifting in sheets.
How long does pool leak detection take?
Most domestic pools are diagnosed in a single visit. Repairs are scheduled once you have approved the written quote.
Book pool leak detection in Cape Town
We cover the whole of Cape Town with the same team and the same guarantee. See the full service on our pool leak detection page or browse swimming pool repairs.
Call / WhatsApp a photo of your pool for a free quote: 069 955 1310
Email: info@gibbspools.co.za
10 Year Guarantee
