Pool Losing Water? Evaporation vs a Leak in Southwest Florida

You are topping the pool up more than you used to, and you have decided it is the heat. That is the right first assumption, and about half the time it is wrong.

The difference matters more than it sounds. Evaporation is free and self correcting. A leak dilutes your chemistry every time you add water, drops the level below the skimmer and starves the pump, and if it is underground it washes fill out from under your deck long before anything looks wrong from the surface. The gap between finding one in month one and finding it in year two is usually the difference between a repair and a rebuild.

Here is how to tell which you have, how to test it without getting a false answer, what the fix costs, and the one thing about Florida evaporation that almost every article on this subject gets backwards.

How Much Water Loss Is Actually Normal Here

Measure from a fixed reference rather than by eye. The tile line, the skimmer throat, or a pencil mark on the tile all work. A quarter of an inch a day is around two inches a week, which looks alarming in a bucket and is entirely ordinary in a pool.

The Thing Most Articles Get Backwards About Florida Evaporation

You will read, on a lot of pool sites, that Florida humidity increases evaporation. It does the opposite.

Evaporation is driven by the difference between the water vapour pressure at the pool surface and the vapour pressure of the air above it. The drier the air, the steeper that gradient and the faster water leaves. Humid air narrows the gradient, which slows evaporation down. It is why a wet towel dries in an hour in Phoenix and sits damp all afternoon in Fort Myers.

What actually drives water loss here is heat, direct sun, wind across the surface, long pump run times, splash out from heavy use, and a heater if you run one. Humidity works against all of it.

The practical conclusion is the useful part, and it favours investigating rather than waiting. A pool in Southwest Florida evaporates less than a pool at the same temperature in a dry climate. So when a pool here is losing water faster than the table above, the humid air makes a leak more likely as the explanation, not less. “It is just the Florida heat” is the most expensive assumption in this article.

The Bucket Test, Done So the Answer Is Actually Right

The bucket test compares your pool against a control that can only lose water to evaporation. Done properly it is reliable. Done casually it produces a confident wrong answer, which is worse than not testing.

The steps

• Bring the pool to its normal operating level first.
• Fill a plastic bucket with pool water to about three inches from the top.
• Stand the bucket on the second step, so it is partly submerged and the water in it sits at roughly pool temperature. A bucket sitting on the hot deck will evaporate faster than the pool and will tell you that you do not have a leak when you do.
• Mark the water level inside the bucket and the pool level outside it, on the bucket wall, with tape or a marker.
• Wait 24 to 48 hours.
• Compare the two drops. Equal means evaporation. The pool dropping more than the bucket means a leak.

The conditions that void the result

• Nobody swims. Splash out is not evaporation and it will read as a leak.
• No rain during the test. Rain refills both, unevenly, and the test is meaningless.
• Do not top the pool up partway through.
• Keep the pump on its normal cycle for the whole test, and do not change the schedule mid way.
• Turn off any waterfall, fountain, or spillover feature. Moving water evaporates considerably faster than still water.

Worth running it twice, once with the pump running as normal and once with the equipment off for the full period. If the pool only loses water while the pump is running, the leak is almost certainly on the pressure side, in the return plumbing. If it loses water only with the pump off, suspect the suction side or the skimmer. That single observation saves real time on the diagnostic and is worth mentioning when you call.

The Other Signs, Beyond the Test

You are adding water every few days

Automatic fillers hide this completely, which is why leaks on pools with autofill often run for a year or more. If you have one, check your water bill rather than the pool.

A water bill that stepped up and stayed up

Not a gradual seasonal rise, a step change that never came back down. That pattern is a leak, not a habit.

Soft, wet, or sinking ground near the pool

Spongy grass, soil that stays damp between rains, a paver or a section of deck that has started to sit low or rock underfoot. In sandy Southwest Florida fill this is often the first visible sign of an underground line leak, and by the time it shows, material has already been moving for a while.

Cracks, or gaps opening at the tile line

Hairline cracking in the shell, a separation between tile and coping, or grout that keeps failing in the same spot. Small structural cracks leak slowly and widen, and the ones at the waterline are the easiest to dismiss. Tile replacement or resurfacing is where these end up if left.

Air in the system

Bubbles from the return jets, a pump that keeps losing prime, or air collecting in the pump basket usually means a suction side leak drawing air in rather than water out. Worth having the pump and plumbing checked rather than living with it.

Chemistry that will not hold

Constant top ups dilute everything and dump fresh fill water into the pool, which in this region is hard and carries its own calcium load. If your chlorine and stabilizer keep drifting down for no reason you can identify, and balancing never sticks, the water going in is the reason.

Where Pool Leaks Actually Happen

Roughly in order of how often we find them:

• The skimmer. The most common single location. Ground movement and thermal expansion crack the joint between the skimmer body and the shell. Frequently the cheapest fix on the list.
• Return fittings and jets. Constant pressure works on the seals and the surrounding finish.
• Light niches and conduit. Water finds its way around the fitting and, in some cases, tracks away down the conduit.
• Underground plumbing. Suction and return lines running under deck and soil. The hardest to find, the most expensive to reach, and the one that does structural damage while it hides.
• The equipment pad. Weeping unions, a failing pump seal, a valve or a filter clamp. The easiest to spot because you can see it, and the most commonly ignored for the same reason. Equipment repair handles these.
• The shell itself. Structural cracking, failed plaster, or a compromised bond beam. Least common, most serious.

Bucket Test Says Leak? Let Us Find It

Call A&E Pools at (239) 888-6617 and we will locate it. We pressure test the lines, dye test the suspect points, and use listening equipment on the underground runs, so the leak gets found before anything gets dug up.

Book a leak detection through our contact page, or read more about how we approach leak detection first.

What Professional Leak Detection Involves

Worth knowing, because “advanced technology” tells you nothing and the actual process is straightforward.

Pressure testing the plumbing

Each line is isolated and pressurized independently. A line that holds pressure is intact. A line that loses it is the one leaking, and now the search is narrowed from the whole pool to a single run. This is usually the first step and often the most informative.

Dye testing

With the pump off and the water still, dye released near a suspect point will be drawn into a crack that is moving water. Simple, cheap, and the standard method for confirming skimmer, light niche, return fitting, and shell cracks.

Acoustic listening

Water escaping a pressurized underground line makes a sound. Ground microphones let a technician follow that sound along the run and mark the spot on the surface, which is the difference between opening one square of deck and opening the whole thing.

Camera inspection

A scope run through the lines finds breaks, collapses, and root intrusion, and shows the condition of the pipe rather than just the location of the failure. That matters when deciding whether to repair a section or reroute it.

The point of all four is the same: know exactly where it is before anything is broken open. A leak located precisely is a small repair. A leak found by excavation is a large one.

What It Costs to Find and Fix

Published market ranges, sourced, so you have a sense of scale before you call. These are not our quote, and your pool will land where it lands.

Note the shape of that table. Detection runs $400 to $1,000 on an inground pool, and it is what keeps you out of the $1,000 to $4,000 underground plumbing bracket by finding the leak before it becomes an excavation. Detection is not an extra cost on top of the repair. It is the thing that decides how big the repair is. Figures from HomeGuide’s 2026 leak detection and leak repair data.

Why a Leak Costs More Here Than It Would Elsewhere

Three regional factors compound it.

Most pools here sit in sandy fill with a high water table. A leaking underground line does not pool up visibly, it moves fill. The material under your deck migrates, voids open, and eventually pavers settle, coping separates, or a slab cracks. The leak might be a $1,000 repair. The deck sitting on top of what it washed out is a separate job entirely.

Second, the water table itself. Ground water sits high after the rainy season, which is why a chronically low pool is a genuine structural risk rather than an inconvenience, and why nobody should be draining a pool here to look for a leak.

Third, our pools run twelve months a year. There is no closing, no winter inspection, and no annual point at which somebody looks at the whole system properly. A leak that would be caught at a northern pool’s spring opening can run undetected here for years. That is one of the better arguments for a weekly service visit, where somebody is watching the level week to week rather than noticing it in hindsight. What skipping that actually costs covers the wider maths.

Reducing Evaporation, Realistically

Most advice on this subject tells you to buy a pool cover. On a screened Southwest Florida pool that is close to useless: your lanai is already cutting wind and direct sun, which is most of what a cover does, and a cover is a liability rather than an asset going into hurricane season. What actually moves the number here:

• Turn off waterfalls, fountains, and spillovers when nobody is using them. Moving, aerated water evaporates dramatically faster than still water, and a decorative feature running all day is often the single largest source of loss on a pool.
• If you heat the pool, drop the set point a couple of degrees in summer or stop heating altogether. Warmer water evaporates faster, and heating in July is rarely doing much for anyone.
• Run the pump for turnover, not for the sake of it. Circulation matters, and there is a point past which you are only moving water and losing it.
• Keep the level at the middle of the skimmer throat rather than brim full. A high level splashes out faster and gains you nothing.
• Repair the equipment pad drips. A weeping union looks trivial and runs continuously.

And do not chase evaporation at the expense of water quality. Underfiltering a Florida pool in August to save an inch a week is how you end up with a green pool instead.

Why Southwest Florida Homeowners Call A&E Pools

A&E Pools is a family owned pool company on Jetport Commerce Parkway in Fort Myers, licensed in Florida as CPC1459515, building and servicing pools across the region since 2017. On leaks that matters more than it does elsewhere on the blog, because we build these pools. We know how the plumbing is routed, where the skimmer ties into the shell, and what a bond beam looks like when it is failing, which is what shortens the search.

We serve Fort Myers, Cape Coral, Estero, Bonita Springs, and Naples. See what we have built, read what customers say, check the areas we cover, or browse our full service and maintenance range.

Frequently Asked Questions

How much water loss is normal for a pool in Florida?

About a quarter of an inch a day on a typical summer day, which is roughly two inches a week. Up to half an inch is still plausible in hot, windy, or unscreened conditions, or if the pool is heated. Consistently more than half an inch a day is not evaporation, and that is the point to run a bucket test.

Is my pool leaking or just evaporating?

The bucket test settles it. Stand a bucket of pool water on the second step so it sits at pool temperature, mark the level inside and the pool level outside, wait 24 to 48 hours with no swimming and no rain, and compare the two drops. Equal means evaporation. The pool dropping more means a leak.

Does Florida humidity make pools lose more water?

No, the opposite. Evaporation depends on the vapour pressure gap between the water and the air, and humid air narrows that gap, which slows evaporation. Heat, sun, wind, splash out, water features, and heating are what drive loss here. Because our air is humid, unexplained water loss in Southwest Florida is more likely to be a leak than the same loss would be in a dry climate.

How much does pool leak detection cost?

Published 2026 ranges put leak detection at $400 to $1,000 for an inground pool and $100 to $500 above ground, with a plumbing pressure test at $150 to $500. Detection is what keeps a repair small: finding a line leak precisely avoids excavation, which runs $100 to $300 an hour on its own.

How much does it cost to fix a pool leak?

Inground leak repair averages $500 to $1,500 and up. By type, published ranges are $50 to $300 for a skimmer, $700 to $2,500 for a main drain, $1,000 to $4,000 for underground plumbing, and $2,000 to $5,000 for a liner replacement where one applies. Skimmer leaks are both the most common and among the cheapest, which is a good reason not to put off the diagnosis.

Can a pool leak damage my deck or patio?

Yes, and in Southwest Florida this is the real risk. An underground line leaking into sandy fill moves the material rather than pooling visibly, so voids open under the deck. Settling pavers, coping pulling away, or a slab that cracks or rocks underfoot are usually late signs that this has been happening for a while.

Should I drain my pool to look for a leak?

No. The water table here sits high, particularly after the rainy season, and an empty or heavily drained pool can lift, crack, or shift out of position. Leaks are located with pressure testing, dye testing, and listening equipment, with the water left in. Draining also destroys the evidence, because a dye test needs still water to work.

Can I find the leak myself?

You can narrow it down usefully. The bucket test tells you whether there is one, running it twice with the pump on and then off tells you whether it is pressure side or suction side, and a dye test at the skimmer, the lights, and the returns will find a fair proportion of shell side leaks. Underground plumbing is where it stops being a homeowner job, because locating it needs pressure testing and acoustics, and guessing means digging.

Stop Topping It Up and Find Out

If the bucket test came back badly, or you have been adding water for months and telling yourself it is the heat, call A&E Pools at (239) 888-6617 or request a leak detection through our contact page. We will find it, tell you what it is, and quote the repair before anything gets opened up.

Serving Fort Myers, Cape Coral, Estero, Bonita Springs, and Naples. Licensed Florida pool contractor CPC1459515, family owned since 2017.

If the answer turns out to be the shell rather than the plumbing, we handle resurfacing and remodeling too, and financing if it is a bigger job than you planned for. More about us.