Port St. Lucie Leak Detection Pool water stops at the skimmer line: the most common leak in Florida
Where the water stops is the most valuable piece of information in pool leak work, and if yours stops at the bottom of the skimmer mouth, you are looking at the most common leak on Florida gunite pools.
Why the stopping level tells you so much
A pool leaks only while there is water above the hole. Once the level drops below the leak, the loss stops. So:
| Water stops at | Likely leak |
|---|---|
| Bottom of the skimmer mouth | Skimmer throat or the skimmer-to-shell joint |
| Around the light | Light niche or conduit |
| A few inches below a return fitting | Return fitting or its plumbing |
| Halfway down the wall | A shell crack or a fitting at that level |
| Keeps going to the floor | Main drain, deep plumbing, or a floor crack |
| Only drops when the pump runs | Pressure-side plumbing |
| Only drops when the pump is off | Suction-side plumbing |
Why skimmers fail
The skimmer is a moulded plastic box cast into a concrete shell. Plastic and gunite expand and contract at different rates, every day, for decades. The joint between them opens. Add the throat itself, which is thin plastic that can crack, and the connection to the skimmer’s own plumbing underneath, and you have three failure points within about a foot of each other.
In Florida specifically:
Thermal cycling is relentless. Long hot seasons, warm pool water, and a deck that reaches high surface temperatures work that joint every day.
Age is the main variable. Pools twenty years and older are where most of these live, and the Treasure Coast has plenty of them.
Deck settlement on the sandy soils here can put load on a skimmer that it was not designed to carry.
Check this first (twenty minutes, free)
- Note exactly where it stops. Let it stabilise and mark the tile. That level is your best diagnostic.
- Do the bucket test. Fill a bucket, set it on a step, mark inside and outside levels, wait 24 hours with the pump running normally. If the pool drops more than the bucket, you have a leak. If they match, it is evaporation. The bucket test post has the full method.
- Look into the skimmer throat with a torch. Visible cracks in the plastic, or a gap where the plastic meets the concrete, are what you are looking for.
- Check whether it drops faster with the pump on or off. If the rate is the same either way, that points to a static leak like the skimmer rather than a plumbing leak.
- Look for a wet area in the deck or yard on the skimmer side.
What the repair involves
Sealing the joint. Where the separation is accessible and the skimmer body is sound, the joint is cleaned out and sealed properly. Low end of the range.
Partial rebuild. A cracked throat or a more substantial separation means rebuilding that section, which is more work and usually means cutting some tile and possibly some deck.
Full skimmer replacement. The skimmer body itself has failed and comes out. This requires a deck cut, and it costs more than the published range. That should come up before you approve anything, not after work has started.
$300–$800 covers the first two, which is where most Port St. Lucie skimmer repairs land. The skimmer leak repair page has the detail and the pricing page has every published range.
The honest note about DIY
Underwater epoxy putty on a visible crack in a skimmer throat is a legitimate temporary fix and sometimes buys a season. Two cautions:
It will not seal a separation behind the skimmer body, which is where a lot of these actually are, and you cannot see that from inside the throat.
And a putty repair that half works turns a diagnosable leak into a slow one, which is how people spend an entire summer topping up a pool and looking in the wrong places.
Why detection comes first anyway
Even when the symptom points clearly at the skimmer, the detection visit is worth its flat fee, because pools frequently have more than one leak. A pool that has been losing water for a year often has a skimmer separation and a light conduit, or a skimmer and a return fitting. Repairing one and finding the pool still drops is a bad week for everybody.
The visit is a flat $250–$400 for a standard residential pool, and it produces a written report and a separate repair quote. The cost calculator prices it with the repair range attached.
What to expect on the call
Note exactly where the water stops, what the bucket test showed, whether the rate changes with the pump, and roughly how old the pool is. We cover Port St. Lucie, Fort Pierce, Jensen Beach, Stuart, Palm City, Port Salerno, and St. Lucie West.
Frequently Asked Questions
My pool drops to the skimmer and then stops. What does that mean?
It means the leak is at or just below that water level, and on a Florida gunite pool that almost always points at the skimmer. Water stops falling once it is below the leak, which is why where it stops is the single most useful clue you can give a leak detection company.
Why do skimmers leak?
The skimmer is a plastic box set into a concrete shell, and plastic and gunite expand and contract at different rates. Over years that joint opens up. Ground movement, settling, and freeze-thaw are not the issue here; thermal cycling and simple age are.
What does skimmer leak repair cost?
$300–$800 for anything from sealing the skimmer-to-shell joint up to a partial rebuild. A full skimmer replacement requiring a deck cut runs higher, and you should hear that before you approve anything rather than after.
Can I patch it myself with pool putty?
You can, and it sometimes buys a season. Underwater epoxy putty on a visible crack in the skimmer throat is a legitimate temporary fix. What it will not do is seal a separation behind the skimmer body or a cracked throat below the tile line, and pushing putty into a gap you cannot see is how people spend a summer convinced the leak is elsewhere.