In this article
When a pool owner notices the water dropping, the first thought is usually where the leak is. But there is an earlier question: is it a leak at all, or just evaporation? Only then comes the question of location, which can be answered in several ways. Some methods are simple enough to do yourself with household items, while others need equipment and experience.
This is a practical guide to pool leak detection methods, ordered from simplest to most specialised, explaining when each is used, what it tells you and its limits.
The bucket test step by step
The bucket test is always the starting point. Water in a bucket placed in the same conditions as the pool is exposed to the same sun, air and heat. Compare the loss in the bucket with the loss in the pool. If both drop by a similar amount, it is evaporation. If the pool drops clearly more, there is a leak.
What you need
- A sturdy medium-sized plastic bucket.
- Waterproof tape or a marker.
- A stone or small weight in the bucket so it does not float or shift.
Steps
- Set the pool at its normal level, roughly mid-skimmer.
- Place the bucket on the first or second step so most of it is submerged, or secure it at the edge.
- Fill the bucket with pool water to about the same level as the pool.
- Mark the water level inside the bucket, and the pool level on the outside of the bucket.
- Run the pump on its normal schedule, add no water and allow no swimming.
- After a full day, compare how far each level dropped.
- Repeat with the pump switched off and compare.
Reading the result
- Similar loss in bucket and pool: evaporation, no significant leak.
- Pool loses more in both runs: likely a leak in the shell.
- Pool loses more only with the pump on: suspect pressure lines or returns.
- Pool loses more only with the pump off: suction lines are possible, as they may draw air when running instead of leaking water.
The dye test
Once a leak is confirmed, dye helps locate it. A tiny amount of pool leak-detection dye is released near a suspect point in completely still water. If the point leaks, the dye is clearly drawn into the crack or fitting. If not, it stays put or drifts slowly.
- Switch off the pump and wait until the water is completely still.
- Start with the likeliest spots: lights, returns, skimmer, main drain, visible cracks and the wall-floor corner.
- Approach slowly to avoid moving the water and release a drop very close to the point.
- Watch it for a few seconds.
Its limits: you need a rough idea of where to look, deep areas are hard without diving, and it cannot reveal buried pipe leaks.
Line pressure testing
If the bucket test points to pipes, or dye finds nothing in the shell, the next step is pressure testing each line. Each pipe is isolated by plugging it at the pool end and the plant-room end, then pressurised with air or water while a gauge is watched. If pressure holds, the line is sound. If it drops, that line leaks. It identifies exactly which line is at fault, which saves a lot before any digging.
Cameras and listening devices
Underwater cameras
Used to inspect floor, walls and fittings in hard-to-see areas and record images to study later. Special pipe cameras travel inside lines to show breaks, blockages or separated joints.
Listening devices
A leak in a pressurised pipe makes a faint sound the ear cannot hear, but sensitive devices pick it up from the ground surface or in the water. By moving along the pipe route, the technician finds where the sound is loudest and marks the dig point precisely instead of breaking large areas.
Quick comparison
| Method | What it reveals | Who does it |
|---|---|---|
| Bucket test | Whether there is a leak and its link to the pump | Owner |
| Dye test | Leak points on walls, fittings and reachable floor | Owner or technician |
| Line pressure test | Which pipe leaks | Specialist |
| Camera | Hidden cracks and pipe interiors | Specialist |
| Listening devices | Leak position along a buried pipe | Specialist |
When to call a specialist
- The bucket test confirms a leak but dye finds no point.
- Loss depends on whether the pump is on or off, pointing to pipes.
- You see damp or sinking around the pool or along pipe routes.
- The leak returns after an earlier repair.
- Loss is large and fast, where delay harms soil and structure.
Before calling, have your bucket test results, photos and notes ready. To see when an engineering inspection becomes necessary, read when a pool leak needs an engineering inspection.
YAM Pools combines these methods to suit each pool, always starting with the simplest so you do not pay for tests you do not need, then gives you the source and repair method in a written quotation with a written warranty on workmanship. We serve Riyadh and all cities of Saudi Arabia.
Frequently asked questions
How long does a bucket test take?
Usually a full day for each condition, once with the pump on and once off. Repeating it gives a more reliable result, especially in changeable weather.
Can I use food colouring instead of pool dye?
We do not recommend it, as some colours can stain tiles or affect the water. Purpose-made pool leak dye is safer and clearer.
Does pressure testing involve breaking anything?
No, it is usually done through fittings in the pool and from the plant room. Breaking out is only needed to reach the leak once located.
What if the loss is only evaporation?
Good news. You can reduce it with a pool cover or by running water features less in the hottest hours. Keep monitoring the level anyway.
