Pool Leak Detection
Leak detection is a diagnostic service, not a repair. Specialists use pressure testing, acoustic listening and dye to locate a leak precisely — so that the repair excavates one spot rather than a whole yard.
Do the bucket test first
It costs nothing, it takes 24 hours, and every leak-detection company will ask whether you have done it. It also occasionally saves you the call entirely by showing the loss is just evaporation.
- Fill a bucket with pool water and set it on a step. Position it so the water level inside matches the pool level outside.
- Mark both levels and wait 24 hours. Leave the pump running as normal.
- Compare. Equal drop means evaporation. A bigger drop in the pool means a leak.
- Repeat with the pump off. Worse with the pump running points at the pressure side; the same either way points at the shell or a fitting.
- Note where the level stabilises. If it stops at the skimmer mouth or the light, that alone often locates the leak.
What a specialist actually does
Leak detection is a genuine technical discipline, and the equipment is what separates it from guesswork.
Pressure testing
Each plumbing line is isolated and pressurised individually. A line that will not hold pressure is the leaking line — this narrows a whole-yard problem to one circuit.
Acoustic listening
Sensitive listening equipment picks up the sound of water escaping a pressurised line through soil, locating it to within a foot or so.
Dye testing
Dye released near a suspected shell crack or fitting is drawn in visibly if water is escaping there.
Diving inspection
Physical inspection of the main drain, light niches, returns and skimmer throats.
Thermal and camera work
Pipe cameras and thermal imaging where the layout is complex or the leak is elusive.
What it costs
| Service | Cost | Notes |
|---|---|---|
| Basic detection visit | $250–$450 | Pressure test plus visual and dye inspection |
| Full detection with acoustic location | $350–$600 | Where a buried line is suspected |
| Complex or repeat investigation | $500–$900 | Multiple leaks, or unusual construction |
| Detection credited against repair | −$100–$300 | Many companies do this if they perform the repair |
Where leaks usually turn out to be
Structural cracks in the shell get blamed most and are actually among the least common. Fittings and penetrations are the usual answer.
| Location | Diagnostic clue |
|---|---|
| Skimmer and skimmer throat | Level stabilises at the skimmer mouth |
| Light niche and conduit | Very common, easily missed without a dive inspection |
| Return fittings | Loss worse with the pump running |
| Pressure-side plumbing | Worse pump-on; wet or green ground along the run |
| Suction-side plumbing | Air in the pump basket; worse pump-off |
| Main drain | Loss continues below every other fitting |
| Shell crack | Visible crack; loss steady regardless of the pump |
| Liner tear | Vinyl pools; often locatable by dye or by eye |
What to have ready when you call
- Your bucket test results. Both runs — pump on and pump off. This is the most useful thing you can provide.
- Inches lost per day. A number, not "a lot". It sets expectations about what is being looked for.
- Where the level stabilises. Often locates the leak before anyone arrives.
- Pool construction type. Gunite, fiberglass or vinyl liner — different techniques apply.
- Any recent work. Landscaping, a new deck, or plumbing work can all be relevant.
- Photos of wet ground. An unusually lush or soggy patch is a strong lead.
What this project needs measured
Measurements are only requested when they change the price of the work you selected. Everything below is collected inside the estimator — you can enter dimensions you already know or measure as you go.
Required
No measurement required
This project is diagnosed from symptoms and equipment details rather than dimensions.
What the estimator will ask you
- How much water you are losing per day
- Bucket test results, if you have done one
- Whether loss is worse with the pump running or off
- Whether the level stabilises at a particular height
- Any wet or unusually green ground nearby
- Air bubbles in the pump basket
- Pool construction: gunite, fiberglass or vinyl liner
- Photos of the pool and equipment pad
How to read a PoolSavr estimate
- Step 1
Instant estimate
Based on your project selections and general pricing assumptions. Useful for deciding whether a project is realistic.
- Step 2
Measured estimate
Uses your pool, spa, or deck dimensions to price the work against the areas actually being resurfaced, tiled, or replaced.
- Step 3
Contractor proposal
Prepared by a licensed professional after inspecting the site. This is the only number that becomes a contract.
PoolSavr is an estimating and matching platform. We do not perform pool work ourselves — licensed local professionals do. Contractors pay PoolSavr for qualified project leads, which is how the estimating tools stay free for homeowners. A PoolSavr estimate is a planning range, never a guaranteed quote — read thefull estimate disclaimer.
Frequently asked questions
- How much does pool leak detection cost?
- Typically $250–$600 depending on how much equipment the job requires. Many companies credit part or all of the detection fee against the repair if you use them for it, so ask when booking.
- How do professionals find a pool leak?
- By isolating and pressure-testing each plumbing line individually to find which will not hold pressure, then using acoustic listening equipment to locate the escape point through the soil. Dye testing and diving inspection cover the shell, fittings and light niches.
- Should I do anything before calling?
- Do the bucket test, twice — once with the pump running and once with it off. Note how many inches you lose per day and whether the level stabilises at a particular height. That information often halves the diagnostic work.
- Can leak detection find a leak under the deck?
- Yes. That is precisely what pressure testing and acoustic location are for — they identify which line is leaking and where along its run, so the repair excavates one spot rather than lifting the whole deck.
- Is it worth paying for detection, or should I just repair?
- Detection first, essentially always. Without it, a repair is excavating on a guess, and pool plumbing runs under decks and hardscape. Spending $350 to avoid opening the wrong section of deck is straightforwardly good value.
Ready to see what your project costs?
Start with the work you are considering. You will get a preliminary range before anyone asks for your phone number, and you decide whether to request a contractor review at the end.