Pool leak repair in Phoenix starts with a question most owners in milder places never have to ask: is this pool actually leaking, or is the desert just drinking it? Valley pools lose a surprising amount of water to the air every summer. A leak hides inside that loss until the numbers stop adding up.
This page shows how to tell the two apart, how to run the bucket test safely, where leaks usually hide, what a leak detection visit involves, and how patches and crack repairs work. It also covers who in Arizona is licensed for which repairs.
Phoenix Pool Cleaning Pro does not find or fix leaks. It is a free phone line. Call (623) 240-0428 any hour, an automated assistant asks what the pool is doing, and the call is transferred to an independent, locally owned pool service company. That company hunts down the leak, prices the fix, makes the repair and sends you its own bill.
Evaporation or a leak in a Phoenix summer
Start with what normal looks like. The Arizona Department of Water Resources puts average evaporation in Phoenix at about six feet of water a year, most of it in summer. A City of Mesa chart for a 400 square foot pool adds up to about 79 inches a year, close to 20,000 gallons. A similar table from the City of Scottsdale shows the loss peaking at about 10.8 inches in June, which works out to roughly a third of an inch a day, and falling to about 2.6 inches in January.
So a pool that drops a quarter or a third of an inch on a hot, dry, breezy June day may be perfectly sound. Water features, a spa spillover, heavy splashing and wind all add to the loss. What should get your attention is a drop that is clearly bigger than the season explains, a drop that continues in winter when evaporation is low, or a pool that loses more when the pump is running than when it is off.
Leaks are not rare. The City of Mesa estimates that up to 30 percent of pools may have a leak. An autofill can hide one for months, with the only clue a higher water bill, which is one more reason to check the meter or the bill against last year's.
The bucket test, step by step
This is the standard way to separate evaporation from a leak, and it needs nothing more than a bucket and a marker. The bucket and the pool sit in the same sun and wind, so they should lose about the same amount to evaporation.
- Turn off the autofill if the pool has one, so it cannot top the pool up during the test.
- Fill a bucket with pool water and set it on the first or second step, so the bucket's water level is close to the pool's.
- Mark both levels. Mark the water line inside the bucket, and mark the pool's level on the tile or skimmer with tape or a grease pencil.
- Run the pump on its normal schedule and leave everything alone for two to three days. Calm, dry days give the cleanest result; rain or strong wind can throw it off.
- Compare the drops. If the pool fell noticeably more than the bucket, the pool is losing water some other way.
- Optional second round: the City of Mesa suggests measuring the loss over 24 hours with the pump running, then over 24 hours with it off. If more water goes with the pump running, the plumbing is the likely cause; if the loss is about the same either way, the shell, liner or fittings become more likely.
Keep children away from the pool while you work around it, and never leave a child alone near the water. Do not climb in to inspect anything while the pump is running.
Where pool leaks hide
Most leaks show up at the places where something passes through the pool shell or where two materials meet. Water can also leave from plumbing under the deck or from the equipment pad. Use this table to describe what you see when you call.
| Where | Clues you might see | Typical repair |
|---|---|---|
| Skimmer throat | Water stops dropping at the bottom of the skimmer opening; a crack or gap where the skimmer meets the tile or shell | Underwater putty or sealant at the joint, or skimmer repair or replacement for a cracked body |
| Light niche | Water stops dropping at the light; a gap around the conduit at the back of the niche | Sealing the conduit and niche with a pool rated sealant. The light's wiring is electrical work |
| Return and other fittings | Dye pulls toward a return, cleaner line, drain or step jet | Sealing or replacing the fitting and patching the plaster around it |
| Underground plumbing | Bigger loss with the pump running, wet or sinking deck spots, air in the pump basket, cracks in the deck | Pressure testing each line, then digging or cutting the deck to repair the broken section |
| Equipment pad | Drips or puddles at the pump, filter, valves or heater, or water from the backwash line when it should be closed | Replacing o-rings, unions, seals or valves, often a smaller fix |
| Cracks in the shell | A visible crack in the floor, walls or the tile line, sometimes with dye drawn into it | Patching for minor cracks; for structural cracks, finding out why the shell moved before repairing it |
- Note where the water stops. If the level falls and then holds at a certain height, the leak is often at or near that height, such as the skimmer or the light.
- Walk the equipment pad and look for drips, wet dirt or puddles, without opening anything.
- Look at the deck for new cracks, damp patches or spots that have settled.
- Check the pump basket lid for air bubbles, which can mean a suction side leak.
What pool leak detection involves
Leak detection is a process of narrowing things down. A careful pool technician usually works from the simplest checks to the more involved ones.
- Confirm the loss. Review the bucket test, the water bill or the autofill, and how the level behaves with the pump on and off.
- Look over the equipment and deck. Many leaks turn out to be at the pad.
- Dye testing. With the water still, a small amount of test dye is released right next to fittings, cracks, lights and the skimmer. If the dye is pulled into a gap, water is leaving there. The dye has to be very close to the leak to show it, so this often means the technician gets in the pool.
- Pressure testing. Each plumbing line is plugged and pressurized. A line that will not hold pressure is leaking somewhere along its length.
- Listening equipment. Electronic listening devices on the deck, or hydrophones in the water, help pinpoint where a line is leaking underground, so less deck has to be opened. The City of Mesa suggests asking whether a company uses tools such as sonar, infrared thermography or ultrasound.
Ask for a written summary of what was tested and what was found. If a line has to be dug up, ask how much deck will be cut and how it will be patched.
Patching a pool: what works with the water in
Small leaks in the shell or around fittings are often fixed without draining. Two part epoxy putties sold for pools are made to harden underwater; the area is cleaned, the putty is mixed and pressed into the crack or around the fitting, then smoothed. It is quick and keeps the pool full, which matters in a city that asks residents to drain pools only rarely. Larger cracks, skimmer replacement and buried plumbing are bigger jobs.
Good candidates for an underwater patch
- A small crack or chip that dye shows is leaking
- A gap between a fitting and the plaster
- The joint where the skimmer meets the shell
- A small hole or tear in a vinyl liner, with a vinyl patch
When a patch is not enough
- Plaster that is soft, hollow or flaking over a wide area
- A crack that keeps growing or runs through the shell
- A leak in buried plumbing
- Several leaks across an old, worn surface
When the surface itself is worn out, the answer may be replastering or another new interior rather than one more patch. Our pool resurfacing page explains those options, and the guide on whether to repair or resurface a pool helps you weigh the cost of patches against a new surface.
Can a cracked pool be repaired?
Most cracked pools can be repaired. The question is what kind of crack it is. The National Plasterers Council describes closed hairline shrinkage cracks and crazing (a network of fine surface cracks) as cosmetic. Open cracks, and cracks that run all the way through the finish because the structure underneath is moving, need remedial work, and patching them without stopping the movement is a poor fix. A crack that leaks, widens, shows a step from one side to the other, or runs along the tile line and bond beam calls for a diagnosis of the cause before a lasting repair is chosen.
Licensing for leak, plumbing and crack repair in Arizona
Arizona's Registrar of Contractors (ROC) licenses contractors, and the classification matters for leak work. The ROC's R-6 Swimming Pool Service and Repair classification covers servicing pools and minor repairs, but it lists plumbing connections to a drinking water system, gas lines and electrical work beyond the first disconnect as outside its scope, and it does not allow a complete replacement of a plaster or pebble interior or the deck. So a pool company may patch a fitting under its R-6 license, while larger shell, plumbing or replastering work may call for a different classification. Ask the company which license covers the work it is quoting, then confirm it on the ROC contractor search.
Questions worth asking before the leak work starts
- How will you find the leak, and is detection priced separately from the repair?
- What did the dye and pressure tests show, and can I see it?
- Is this crack cosmetic or structural, and how do you know?
- Can it be patched with the water in, or does the level need to come down?
- If water must be removed, where will it go?
- What is your ROC license number and classification?
Pool still dropping after the bucket test? Call any hour, say how many inches it lost in how many days, whether the pump was on, and where in the Valley you are.
Pool leak repair in Phoenix through the free line
The call is free. Tell the assistant how fast the water is dropping, and the pool company hears that summary before it joins the call. If it is busy, it gets your name, phone number, neighborhood and the water loss details so someone there can phone you. Leak testing, the price and the repair are arranged with that company alone.
- Call the numberAn automated assistant answers (623) 240-0428 day or night, weekends included.
- Describe the poolSay what is going on: cloudy or green water, a pump that hums, a heater that will not fire, scale on the tile, and which part of the Valley you are in.
- Get put throughThe call is transferred to an independent, locally owned pool service company, which hears a short summary of the problem before it picks up.
- Deal with them directlyThat company looks at the pool, quotes, does the work and bills you. If it cannot answer, your name, number, area and problem are passed along so it can call you back.
About this line: Phoenix Pool Cleaning Pro is a free phone line, not a pool company. It answers your call and connects you with an independent local pool service company, which inspects, quotes and does the work, and which you pay directly. Companies may pay a referral fee. You never pay the line. See how the line works.
Check the license first. Arizona's Registrar of Contractors (ROC) licenses contractors, and its residential classifications include R-6, Swimming Pool Service and Repair. Repairs, equipment replacement and resurfacing generally call for a licensed contractor; whether a cleaning-only service needs a license is not spelled out, so ask the ROC if it matters to you. Ask the company for its ROC license number and look it up on the ROC contractor search (opens in a new tab) before work begins. The line does not check this for you.
More on leaks, cracks and surfaces
- Pool Repair
- Pool Resurfacing
- Pool Equipment Repair
- Pool Tile Cleaning
- Repair or Resurface a Pool?
- How Often Should You Drain a Pool in Arizona?
Leak help across the Valley
The line takes leak and crack calls from Phoenix and the towns around it.