Pool Losing Water in South Florida? Leak vs. Evaporation — The 24-Hour Bucket Test, Real 2026 Repair Costs & When to Call a Pro

I've been on Florida pool routes since the late 1990s — my father has been a licensed Florida pool contractor since 1989, and he's the one who taught me — and after 25 years and 10,000+ pools serviced from Pompano to Highland Beach, I can tell you the single most frequent panic call we get between April and October starts with the same sentence: “My pool is losing water. Do I have a leak?” The honest answer almost every time: maybe, maybe not— and the cheap 24-hour test below will tell you which one before you spend $400 on a leak detection company.

The fastest decision: bucket test before anything else

You do not need to call us, a leak company, or a pool store before you run this test. Twenty minutes of work, a 5-gallon bucket, masking tape, and a Sharpie. Run it and 80% of homeowners get the answer without spending a dollar.

1. Fill a 5-gallon bucket with pool water to about 4 inches from the top. Place it on the second step inside the pool (so the bucket water and the pool water are at similar temperature).
2. Mark the water level inside the bucket and outside the bucket (on the pool tile) with tape.
3. Run the pump on its normal schedule. Do not add water. Do not run the autofill. Do not swim.
4. Come back in 24 hours. Re-mark both levels. Measure the drop on each.

Bucket drop = pool drop: evaporation, no leak. Pool drop > bucket drop:leak, by exactly that gap. Run it twice if you want to be sure — with screen-off pools or windy days, single-test results swing.

Normal Florida evaporation rates — what you should expect

I get yelled at by homeowners every May who think their pool is leaking when it's actually doing exactly what every uncovered South Florida pool does in summer. The numbers:

For more depth on Florida-specific evaporation drivers and pool-cover math, see our library reference on pool evaporation in Florida.

Leak signatures — what tells me it's real on a walk-around

When the bucket test comes back leak-positive, my next 15 minutes are spent looking for one of seven signatures. Each points at a different repair and a different cost band.

The four leak categories — ranked by frequency in our service corridor

1. Skimmer throat / face leak (~35% of confirmed leaks). The throat (the white plastic neck behind the skimmer basket) is the weakest seal in the pool. Florida heat-cycle expansion + freeze-cycle contraction (yes, even Boca gets occasional 38°F nights) cracks the bond between throat and pool shell over 8–15 years. Water drops to mid-skimmer and stops. Fix is hydraulic cement or a foam-injection seal kit — $150–$450 in 2026.
2. Equipment pad fitting / o-ring (~25%). Pump seals, union o-rings, valve diverters, multi-port valves on sand filters, DE filter band clamps. You can see and smell these on a walk-around. Fix is a part swap — $150–$500 typical, same-visit on most service calls.
3. Plumbing line crack under deck or yard (~20%). The expensive one. Suction lines (skimmer/main drain back to pump) and return lines (filter out to pool returns) run under decks and yards. PVC cracks from settlement, root pressure, or 1990s schedule-40 in salt corridors. Fix requires pressure testing, deck cut, repair, recap — $800–$2,800. Worst case ($3K+) is full re-pipe.
4. Light niche or main drain (~15%). Niche conduit leaks (the conduit running back to the junction box becomes the leak path), main drain seal, or main drain plumbing. Diagnosed with dye test by a diver or a leak-detection company. $350–$1,800.
5. Plaster or shell crack (~5%). Rare. Hairline cracks usually staining-visible at the crack line. Pool surface refinish territory if extensive ($7,500–$12,000 plaster resurface).

When to call a leak-detection specialist vs. handle it yourself

Some leaks you find with a Sharpie and a bottle of pH dye reagent in 10 minutes. Others need ultrasonic gear and a diver. The line:

Handle yourself (or have weekly service tech handle on visit)

• Bucket test diagnosis (no cost)
• Equipment-pad o-ring/union/seal swap (visible, smells/looks wet)
• Autofill float valve stuck open (this is a fake leak — the pool is being topped up constantly without you knowing)
• Pool cover off — covered pools evaporate 50–90% less; uncovered is normal

Call a leak-detection specialist

• Bucket test shows >1/2” daily gap with no visible equipment-pad source
• Water drops past skimmer mouth (now you've burned out the pump, separate $1,400–$2,400 problem)
• Soggy yard spot or wet deck patch — underground plumbing
• Loss only with pump on, or only with pump off (suction vs. pressure side)
• Light niche, main drain, or plaster crack suspected

Full diagnostic protocol — bucket test, dye test, equipment isolation — lives in our library article on pool leak detection.

2026 South Florida leak-related cost reference

The hidden “leak”: an autofill float you didn't know existed

Half a dozen times a year I get called to a leak that turns out to be a stuck-open autofill float valve. The pool never visibly drops, but the homeowner sees their water bill triple. The autofill is silently pumping city water in 24/7 to replace water that's leaking out faster than evaporation can explain. Check your meter with everything shut off — if the dial is moving, you have either an autofill stuck open masking a real leak, or a service-line leak between meter and pool. Both are real, both cost real money.

Want a number for your pool? Run it through the calculator

If you're paying a high water bill and not sure whether you're looking at $40 in evaporation or $400 in a leak, run your service quote through our pool service cost calculator— weekly clients get equipment-pad walk-arounds and bucket-test diagnosis included.

The low-risk first step

If the bucket test came back leak-positive, the lowest-risk next step is a free on-site evaluation. We'll repeat the bucket test under controlled conditions, run a dye test at the skimmer throats and returns, isolate the equipment pad with the valves, and tell you honestly whether you're looking at a $150 o-ring or a $2,800 deck cut. Whether you hire us or not.

Florida's Best Pools is family-owned, CPO C-105377, fully insured, and runs weekly routes through Boca Raton, Delray Beach, Fort Lauderdale, Highland Beach, Boynton Beach, Pompano Beach, Coral Springs, Coconut Creek, Wellington, and the surrounding South Florida service corridor. Same tech every visit (once your route is established). Photo-documented service reports on request. Month-to-month — no long-term lock-in. Built around 40+ years of combined founder experience between Matt Balog, Joe Ford, Ronald Liddell, and Doug Santiago.

Request a free leak evaluation or call 954-347-1120.

Frequently Asked Questions