Losing water · leak detection · leak repair
Pool Leak Detection and Repair in Walnut Creek
Start with a 24-hour bucket test. If the pool drops more than the bucket, it is leaking, and a leak technician can usually find the spot with pressure, dye and listening tests. Detection averages about $300 nationally (Angi).
Water is money in summer. If the level is falling fast, call now.
Talk it through first
(925) 574-5921Tell the pro how fast the level is dropping, whether it changes with the pump on, and where it stops.
Request a QuoteStep one
Leak or evaporation? Run the bucket test
Hot, dry, windy East Bay days evaporate a lot of water, so a dropping level alone does not prove a leak. The bucket test compares your pool against evaporation under identical conditions.
- Fill a bucket with pool waterSet it on the first or second step so the water inside is close to the pool level.
- Mark both levelsMark the water line inside the bucket, and the pool level on the outside of the bucket (tape works).
- Run the pump normally for 24 hoursTurn off the autofill and do not add water or swim.
- CompareIf the pool level dropped more than the bucket level, the difference is a leak. Repeat once with the pump off to see which side of the system is leaking.
Decision flow
Narrow it down before the tech arrives
- 1
Did the pool drop more than the bucket?
NoEvaporation. Recheck after a heat wave or if the bill jumps.YesIt's a leak. Go to step 2. - 2
Does it lose more with the pump running?
Pump onSuspect the pressure side: return lines, equipment pad fittings, filter or heater connections.Pump offSuspect the suction side or the shell: skimmer, main drain line, light niche, cracks. - 3
Does the level stop dropping at one point?
SkimmerStops at the skimmer mouth: skimmer throat or the seal to the shell.LightStops at the light: light niche or conduit.Keeps goingMain drain, suction plumbing or a structural crack. - ✓
Book a leak detection visit
Share the test results and where the level stopped. That shortens the visit and the bill.
A general troubleshooting pattern, not a diagnosis. Some pools have more than one leak.
Where pools leak
The usual leak points
| Leak point | What gives it away | Typical repair |
|---|---|---|
| Skimmer | Level stops at the skimmer mouth; cracks where the skimmer meets the shell | Seal, repair or replace the skimmer throat |
| Return fittings | Loss mostly with the pump running | Reseal fittings; pressure test the return lines |
| Light niche | Level stops at the light; dye drawn into the conduit | Seal the conduit and niche |
| Main drain | Loss continues to the bottom | Repair or replace the drain body and pipe |
| Plumbing under the deck | Wet spots in the yard, sinking pavers, pressure-test failure | Locate and repair the line, sometimes a reroute |
| Structural cracks | Visible crack with dye pulled into it; calcium deposits | Crack repair; may lead to resurfacing |
How pros find leaks
Pressure, dye and listening tests
- Pressure testing: each plumbing line is plugged and pressurized; a line that loses pressure is leaking. Angi lists $200–$500+ for a line pressure test (Angi).
- Dye testing: a small amount of dye is released next to a suspected spot underwater; a leak draws the dye in.
- Listening equipment: acoustic gear hears water escaping from a pressurized line, so the tech can mark where to dig.
- Equipment inspection: the pump, filter, heater and valves are checked for drips, wet ground and air in the system.
Leak detection is usually done with the pool full. Do not drain a pool to look for a leak unless a pro tells you to.
After it is found
Repair and what comes next
Small fitting and skimmer leaks are often fixed the same visit. Underground line repairs and crack repairs are quoted separately because they depend on what is above the pipe. If the shell needs work, it may be the moment to resurface.
Equipment pad leaks (pump seals, filter O-rings, heater fittings) are covered on the equipment repair page. Costs are on the cost guide.
Answers
Questions people ask
Is pool leak detection expensive?
Angi puts the national average around $300, with in-ground pools at $400–$1,000+. A pressure test of the lines runs $200–$500+.
How much water loss is normal for a pool?
There is no single number. Evaporation depends on sun, wind, humidity and water temperature, which is why the bucket test compares your pool against a bucket on the same day.
Can Gorilla Tape patch a pool leak?
Not on a plaster pool. Tape may slow a vinyl liner tear briefly, but it does not fix a plaster, fitting or plumbing leak.
Should I drain my pool to find a leak?
No. Most leak testing is done with the pool full. Draining a pool also needs a Central San permit in this area.
Keep going
Related repairs and guides
Next step
Losing water? Describe the leak
Share your bucket test result, whether loss changes with the pump on, and where the level stops. A local leak specialist can follow up.
- Resurfacing, leaks, equipment, tile and remodels
- Walnut Creek, Danville, Alamo, Lafayette and nearby
- Ask for a written scope before any work starts
Prefer to talk? (925) 574-5921