PoolLeakFix • Florida Homeowner Guide
Is My Pool Leaking or Is It Just Evaporation?
If your pool water keeps dropping, the real question is simple:
is this normal evaporation, or am I actually losing water somewhere I shouldn’t?
The sections below walk through normal water loss ranges in Florida, what pushes evaporation higher, the red
flags that point to leaks, and a couple of simple tests you can do at home.
How Much Water Loss Is “Normal” in a Florida Pool?
Every pool loses some water, even when it’s perfectly built and there isn’t a single crack or bad fitting.
In Florida, an uncovered pool will usually lose water from:
- Heat – warm water exposed to air.
- Wind – air moving across the surface pulling moisture away.
- Humidity changes – dry air drives evaporation faster.
- Splash-out – people, pets, and games pushing water onto the deck.
- Water features – fountains, bubblers, and spa spillovers.
- Heaters – warm water vs cool air during winter nights.
In realistic terms for Florida:
-
On calmer, milder days with no features running,
about ⅛" to ¼" per day of loss can be normal. -
On hotter, drier, or windier days, or with heaters and water features running, you can see closer to
¼" to ⅜" per day.
Over a week, a healthy pool can easily lose around ¾" to 1½" of water purely from
evaporation and normal use. If your loss sits roughly in that range and conditions line up (sun, wind, heater,
use), that’s your baseline.
Factors That Increase Evaporation (Without Any Leak)
Some pools naturally evaporate more than others because of how they’re built and how they’re run.
These factors don’t “create” leaks, but they can dramatically increase water loss.
1. Water Features
Anything that breaks water up and throws it through the air will boost evaporation:
- Spa spillovers
- Fountains and bubblers
- Deck jets
- Waterfalls and sheer descents
When water is splashing, spraying, or running in thin sheets, it has
more surface area exposed to air and spends more time in the air instead of sitting calm in
the pool. A still pool with no water features running will always evaporate less than the same pool with a spa
spillover and fountain going all day.
2. Heaters
Heated water in cooler air is another big driver. If your pool or spa is sitting in the low 80s while night air
drops into the 50s–60s, you may even see steam coming off the surface. That “steam” is water leaving the pool.
Any time the heater runs regularly in cooler weather, plan on more evaporation than you’d see in summer with
the heater off.
3. Wind and Exposure
A pool that’s fully open to the wind will lose more water than a pool protected by screens, fences, or dense
landscaping. Steady air moving across the surface pulls moisture away and doesn’t give it much chance to fall
back in.
4. Heavy Use and Splash-Out
Any stretch with kids in and out all day, dogs jumping in, guests over, or lots of games will drive splash-out.
That’s not a leak; it’s simply water being pushed onto the deck and yard instead of staying in the shell.
Red Flags That Point Toward a Leak
Evaporation tends to be fairly steady and closely tied to weather, features, and usage. Leaks, on the other
hand, are usually paired with other warning signs. Here are the ones worth paying attention to:
- Loss around ½" per day or more, several days in a row.
- Fast drop even on mild, calm days with the heater and water features turned off.
- Soft or mushy spots near the deck or around the pool perimeter.
- Areas that stay damp or wet long after they should have dried out.
- Deck settling, new cracks, or hollow-sounding spots when you tap the concrete.
- Pump that pulls air, loses prime, or gurgles repeatedly.
- Visible cracks around skimmers, returns, tile line, or lights that look suspicious.
- Autofill running constantly, but the pool never quite looks “full.”
- A water bill creeping up with no other obvious explanation.
One sign by itself doesn’t automatically prove a leak, but when you combine a faster drop with several of these
clues, you should treat it as more than just normal evaporation.
Quick “Mark-the-Tile” Test
Before you do anything more involved, a simple mark-the-tile test can tell you whether you’re in the rough
normal range or something more concerning.
- Bring the water level to where you normally keep it.
-
Use a piece of tape or a grease pencil to mark the waterline:
- On the tile, or
- Inside the skimmer throat.
- Run the pool as you normally do for 24 hours.
- Check how far the water dropped relative to the mark.
If the drop is roughly in that ⅛"–¼" per day range and conditions were warm or
breezy, that may be normal. If you are consistently seeing close to ½" per day or more,
it’s worth moving on to a more precise test.
The Bucket Test: Evaporation vs Leak
The bucket test compares evaporation inside a small container with evaporation in the pool. It’s a
straightforward way to tell if your pool is losing water faster than it should.
How to Set Up the Bucket Test
- Fill a sturdy plastic bucket about ¾ full with pool water.
- Place the bucket on the second step so it sits securely with part of it underwater.
- Adjust the water inside the bucket so it’s roughly level with the pool water outside.
- Mark the water level inside the bucket.
- Mark the water level on the pool side (on the tile or inside the skimmer).
Run the Test
-
Run the pool as you normally do for 24 hours:
- Same pump schedule.
- Same heater usage (on or off).
- Same water features (on or off) you’re trying to test.
-
After 24 hours, compare the drop:
- How far did the water drop inside the bucket?
- How far did the water drop in the pool?
How to Read the Bucket Test
- If the pool and bucket dropped about the same amount, your loss is likely evaporation.
-
If the pool dropped significantly more than the bucket, that usually points toward a leak
somewhere in the pool system.
You can repeat this test in different configurations:
- Heater and features off (baseline).
- Heater on, features off.
- Heater and features running the way you normally use them.
The differences between those runs show how much extra loss comes from the way you run the pool versus water
leaving through a leak.
How Autofill Systems Hide Leaks
Autofill systems make leaks harder to notice because they keep “fixing” the symptom. When the water level drops,
the autofill adds more water automatically, and the pool always looks normal at a glance.
If you suspect a leak and have an autofill:
- Turn the autofill off temporarily.
- Run the mark-the-tile or bucket test for a few days.
- Watch how far the water level falls when it isn’t being topped off.
If the level falls quickly once the autofill is off—or the bucket test shows the pool dropping more than the
bucket—you’re likely dealing with more than just evaporation.
When to Treat It as a Leak and Call a Pro
You should seriously consider professional leak detection if:
- You’re consistently losing around ½" per day or more.
- The bucket test shows the pool dropping faster than the bucket.
- You’ve turned off heaters and water features and loss is still high.
- You see soft spots, persistent damp areas, or changing deck conditions.
- The pump keeps pulling air, losing prime, or making unusual noises.
- The autofill runs constantly and your water bill is higher than expected.
A solid leak detection visit typically includes:
- Visual inspection of the shell, tile line, skimmers, and fittings.
- Pressure testing of plumbing lines to check for underground leaks.
- Dye testing at skimmers, cracks, lights, returns, and other suspect areas.
- In some cases, electronic listening equipment to pinpoint leaks in buried lines.
The goal is not just to say “yes, you have a leak” but to identify where the water is going
and outline a clear repair plan.
Recommended Tools for Home Testing
You don’t need specialty equipment to get started. A few simple items make testing easier:
- A sturdy plastic bucket (5-gallon style works well).
- A grease pencil or waterproof marker for marking waterlines.
- Painter’s tape for temporary reference marks on tile or deck.
-
Optional: a simple pool leak detection dye kit for checking cracks around skimmers, returns,
and fittings.
View basic leak detection dye kits
Bottom Line
Some water loss is normal in a Florida pool, especially with heat, wind, heaters, and water features running.
The key is the amount of loss, the pattern over time, and the
extra clues you see around the deck, equipment, and yard. Simple checks like the
mark-the-tile test and bucket test quickly show whether you’re in a normal range or clearly outside it.
When the numbers and the warning signs line up, treat it like a leak. Getting a clear answer now is usually
much cheaper than ignoring it while water quietly washes out soil under your deck or pushes your water bill
higher month after month.