Pool Light Leak Repair in Port St. Lucie

A leaking pool light drains the pool to the top of the light niche and stops — because the leak isn’t the light itself, it’s the niche and the electrical conduit behind it, an open pipe below water level that siphons water into the ground when its seal fails. In Port St. Lucie the fix runs $300–$650: dye-confirm the leak, reseal the niche, and pot the conduit with epoxy rated for permanent submersion. No deck cutting in the typical case.

Light leaks are the sneakiest of the common Florida pool failures because nothing looks wrong. No wet deck, no bubbles, no visible crack — just a pool that keeps easing down to the same waterline like it’s doing it on purpose. It is: pools leak down to the level of their leak, then stop.

The anatomy of a light leak

An in-ground pool light sits in a wet niche — a metal or plastic can cast into the gunite shell. From the back of that can, an electrical conduit runs through the shell, under the deck, and up to a junction box near the equipment pad. The conduit exists to carry the light’s cord, but hydraulically it’s a pipe with one end underwater.

The system stays watertight only because of the seal where cord meets conduit — the potting compound at the back of the niche. When that potting fails (age, heat cycles, an old repair done with the wrong material), pool water flows into the conduit and siphons steadily out underground. Because the conduit run is buried, hundreds of gallons a week disappear with zero surface evidence.

The niche itself has a second failure mode: the seal between the niche can and the gunite shell can separate, same story as the skimmer-to-shell joint — dissimilar materials, decades of expansion cycles, sandy-soil settling. Both failure points get dye-tested on any light-leak diagnosis.

Why Port St. Lucie sees so many of these

The pools built during the city’s mid-2000s boom — across St. Lucie West, Torino, and the eastern GDC-platted neighborhoods — are now 15 to 25 years old, and original potting compounds and niche seals from that era are simply timing out. Newer pools in Tradition and Verano aren’t immune (a marginal factory potting job can fail early), but the 2000s cohort is where we find light leaks weekly.

Two local factors make them hide longer here. First, autofill valves: the pool never visibly drops to the light, so the leak announces itself through the City of Port St. Lucie utility bill — tiered water rates plus sewer billed on the same meter — instead of the waterline. Second, salt systems: constant fresh-water replacement dilutes salinity, so the first “symptom” many owners chase is a salt cell that keeps alarming. If you’re feeding a salt pool bags more often than usual, think leak before you think cell.

Confirming it — the dye doesn’t lie

The diagnosis is quick and visual. With the pump off and the water still, a technician dye-tests around the niche: the face seal between niche and shell, the conduit opening at the back of the can, and the cord entry. A live leak pulls dye in a visible stream you could film on your phone. If your pool has been parking at the top of the light, we usually walk in expecting this and walk out with it confirmed — but we still check the skimmer throat, fittings, and tile line while we’re wet, because second leaks on 20-year-old pools are common enough that skipping the check is malpractice. The full diagnostic sequence is on the pool leak detection page.

The repair: reseal and pot — $300–$650

1. Pull the fixture. The light comes out of the niche on its cord slack (they’re installed with extra cord for exactly this).
2. Prep the failure points. Old potting compound and failed sealant come out; surfaces get cleaned and prepped so new material bonds to sound substrate — the step rushed repairs skip, and the reason rushed repairs fail.
3. Pot the conduit. The cord-in-conduit entry is sealed with epoxy potting compound rated for continuous underwater service — closing the siphon permanently while leaving the cord serviceable.
4. Reseal the niche-to-shell joint where dye showed movement there too.
5. Re-test. Dye again after cure. The repair isn’t done because we say so; it’s done because the dye stops moving.

Typical job: a single visit, no deck cut, quoted in writing beforehand per our published pricing. If the niche can itself is corroded through — it happens on older metal niches — that’s a bigger conversation, and you’ll get it straight before any work starts rather than as a change order after.

What it costs to ignore

A conduit siphon runs 24/7, not just when the pump runs. At typical rates that’s real money on a Port St. Lucie water bill — commonly $50–$150 a month between tiered water and sewer — plus the salt and chemicals the fill water endlessly dilutes, plus saturated sand under the deck slowly doing what saturated sand does. Against a $300–$650 one-visit repair, the math never favors waiting. If you’re not sure the light is your problem, run the 24-hour bucket test on the FAQ page first, note where the level stops, and tell us.

We repair light and conduit leaks across Port St. Lucie plus Fort Pierce, Jensen Beach, Stuart, and Palm City — same published ranges everywhere on the Treasure Coast.