Pool leak? How to carry out a simple diagnosis in 24 hours
Your pool is losing water and you do not know whether that is normal? Before calling a professional, there is a simple, free method to find out whether you really have a leak: the bucket test. Here is how to carry it out and interpret the results.
Evaporation or leak: what is the difference?
Every pool loses water every day — that is normal. Evaporation, splashing and the liner account for a loss of 1 to 3 cm per week in summer. Beyond that, suspect a leak.
→ See our article: Why your pool is losing water — and what to do about it
But how can you be sure without dismantling anything or paying for a costly call-out?
The bucket test: the simple, reliable method
What you need
A simple bucket, some water and 24 hours of patience. That is all.
Method
1/ Fill a bucket with water to the brim and place it on the first step of your pool, submerged up to half its height.
2/ Mark the water level in the bucket with a piece of tape or a waterproof marker.
3/ Also mark the pool water level on the edge of the pool or on the skimmer.
4/ Switch off the pump and wait 24 hours without using the pool.
5/ Compare the two drops in level.
Interpreting the results
If the pool and the bucket have lost the same amount of water → it is normal evaporation, not a leak.
If the pool has lost more water than the bucket → you probably have a leak. The difference gives you an idea of how significant the loss is.
If the bucket has lost more water than the pool → the leak is in the bucket!!! That is less serious!
Where should you look for the leak if the test is positive?
The hydraulic circuit
The most common cause. Check the visible fittings around the pump, the filter and the skimmers. A trace of damp or limescale on a fitting is often a giveaway.
The liner, walls or shell
A tear or hole in the liner can cause significant losses, as can micro-cracks in a masonry wall. A polyester shell can also be damaged (this is rarer). Inspect the floor and walls visually, particularly around the return jets and skimmers.
Skimmers and return jets
The seals around skimmers and jets age and can crack. This is a priority check on pools more than 5 years old.
Keep the level topped up automatically during your diagnosis
Whatever the cause of your water loss — leak or evaporation — one thing is certain: letting the level drop exposes your pump to the risk of running dry and can damage your automatic cover or your salt chlorinator.
NivOmatic keeps your pool level constant automatically while you investigate — and permanently afterwards, to compensate for the unavoidable losses due to evaporation.
Protects your pump and equipment
Works without electricity
Installed in 2 minutes
Made in France, 2-year warranty
→ Not sure which model to choose? Read our guide
Frequently asked questions
How long does the bucket test take?
24 hours is enough to get a reliable result. Avoid doing it in strong wind or heavy rain, which would distort the measurements.
Should I switch off the pump during the test?
Yes. The pump circulates water, which changes the levels. Switch it off for the whole duration of the test to get reliable results.
My pool loses 5 cm a week — is that serious?
That is above normal. Do the bucket test straight away and contact a professional if the leak is confirmed. A loss of 5 cm a week in an 8×4 m pool represents about 1,600 litres of water lost every week.
