If you keep topping off your pool every few days, you’re not alone. Pool water loss is one of the most common problems we hear about from homeowners in Fort Myers, Naples, Cape Coral, Bonita Springs and across Southwest Florida. Some of it is normal. Some of it is your pool telling you something is wrong.
This guide explains why your pool is losing water, how to tell evaporation from a leak, and which maintenance issues are worth fixing before they become expensive repairs.
Is Pool Water Loss Normal? Evaporation vs. a Leak
Every outdoor pool loses some water. Sun, wind, heat and low humidity all pull water off the surface. In Southwest Florida’s summer heat, a drop of about ¼ inch per day is common, and roughly 1½ to 3½ inches per week can be normal. Pools with waterfalls, spillovers, fountains or spas lose more because the moving water evaporates faster.
You may have a leak if:
- The level drops more than ¼ inch a day, consistently
- Your autofill runs constantly or your water bill keeps climbing
- You see wet spots, soft soil or standing water near the equipment pad or pool deck
- The pool loses water even on cool, calm, humid days
- You notice cracked tile, loose coping or new cracks in the deck
- The pump loses prime or pulls in air
The Bucket Test: How to Check for a Pool Leak
This simple test takes 24 hours:
- Fill a bucket with pool water, leaving about an inch of room at the top.
- Set it on a pool step so the water inside the bucket matches the pool level outside.
- Mark both water levels with tape or a marker.
- Turn off the pump, autofill, heater and any water features.
- Wait 24 hours, then compare.
If the pool dropped more than the bucket, evaporation alone doesn’t explain it. You have a leak.
Pump On vs. Pump Off: Where Is the Leak?
Once the bucket test points to a leak, this second test helps narrow it down:
- More water loss with the pump running: the leak is likely on the pressure side (after the pump, filter, heater or return lines).
- More water loss with the pump off: the leak is likely on the suction side, or in the skimmer, main drain or shell.
- Same loss either way: look at the shell, tile line, light niche, fittings or the pool finish.
- Level stops dropping at a certain point: that’s a clue. If it stops at the skimmer mouth, check the skimmer and its gaskets. If it stops below the tile line, look at the tile and coping.
Common Maintenance Issues That Cause Pool Water Loss
1. Worn pump lid O-rings and shaft seals
Dried-out or cracked O-rings let water drip and air in. A leaking shaft seal often shows up as drips under the pump or bubbles at the returns. This is usually a low-cost fix, so check it first.
2. Failing backwash and multiport valve gaskets
If water keeps trickling out of the backwash line when you’re not backwashing, an internal gasket has probably worn out.
3. Skimmer problems
A worn gasket or cracked skimmer throat can leak where the skimmer meets the pool wall.
4. A stuck autofill valve
Autofill is convenient, but a valve stuck open can hide a slow leak for months while raising your water bill. Turn it off before testing.
5. Cracked or missing pool tile and failing grout
Your waterline tile does more than look good. Cracked tile, failed grout and loose coping let water get behind the shell, especially with Florida’s heavy summer rain and temperature swings.
6. Cracks or wear in the pool surface
Hairline cracks in the pool finish can leak, especially when combined with ground movement. An aging, rough or peeling surface is a common reason pools start losing water over time. If your finish is stained, cracking or worn, resurfacing may be the permanent fix.
7. Light niches, return fittings and drains
These are common weak points. A leaking light niche often causes water loss only down to the level of the light.
8. Underground plumbing leaks
Pressure-side lines under the deck can leak for a long time before you see any sign. Soft soil, sinking pavers or wet spots near the pool can be clues.
9. Unbalanced water chemistry
Water that stays too acidic (a pH below about 7.2) is corrosive. Over time it can etch the surface, wear down grout, and break down rubber seals and metal fittings. Chemistry alone won’t cause a leak overnight, but neglect shortens the life of everything that holds your water in.
Why Southwest Florida Pools Lose More Water
Our climate is tough on pools:
- Year-round heat and sun speed up evaporation in Fort Myers, Naples and Cape Coral.
- Summer storms can hide a leak or cause overflow, making levels hard to read.
- Sandy, shifting soil can stress pool shells and underground plumbing.
- Salt systems and hard water can wear on tile, finishes and equipment if not maintained.
- Hurricane season can leave debris, cracked decks and damaged equipment.
If your pool is losing water after a storm, don’t assume it’s just evaporation.
What Happens If You Ignore a Pool Leak?
Small leaks rarely fix themselves. Left alone, they can:
- Waste hundreds or thousands of gallons of water a month
- Raise chemical and heating costs
- Wash out the soil under your deck and cause cracking or settling
- Damage pavers, travertine and hardscape
- Force your pump to run dry or pull in air
- Turn a small repair into a major renovation
The sooner you find the source, the cheaper the fix usually is.
When to Call a Pool Repair Professional in Southwest Florida
Call a pro if:
- The bucket test shows a leak
- You’ve checked the equipment and can’t find the source
- You see cracks, hollow-sounding tile or a rough, worn finish
- You’re topping off the pool every few days
- You notice wet ground, sinking pavers or damp spots near the pool
At Infinite Pool Finishes, we’ve served Southwest Florida homeowners and commercial properties for over 20 years. If you need pool repair in Fort Myers or nearby, our team can diagnose the problem and recommend the right fix. If your pool needs more than a patch, we also handle full pool renovation in Naples, FL, including tile and coping replacement and resurfacing.
We serve Fort Myers, Naples, Cape Coral, Bonita Springs, Estero, Sanibel, Sarasota and Marco Island.
Is your pool losing water? Call 239-466-7665 or email office@infinitepoolfinishes.com for a free estimate.
Frequently Asked Questions
How much water loss is normal for a pool in Florida?
Most pools lose about ¼ inch per day, or roughly 1½ to 3½ inches per week, depending on heat, wind, humidity and water features. Losing more than that consistently suggests a leak.
Why is my pool losing water overnight?
Some overnight loss is evaporation, especially when the water is warmer than the air. A large drop points to a leak, a running water feature, or a stuck autofill. Run the bucket test to find out.
Why is my pool losing water when the pump is off?
If the level keeps dropping with the pump off, the leak is probably in the shell, skimmer, light niche, main drain or suction-side plumbing.
How do I know if my pool has a leak or is just evaporating?
Use the bucket test. If the pool drops faster than the bucket over 24 hours, you have a leak.
Is losing ½ inch of water a day a problem?
Usually, yes. That’s about double the typical evaporation rate in warm weather, so it’s worth testing for a leak.
Can cracked tile or a worn pool surface cause water loss?
Yes. Cracks in the finish, failed grout and damaged waterline tile can all leak or let water get behind the shell.
Can low pH cause my pool to lose water?
Not directly. But consistently low pH is corrosive and can damage grout, seals and metal fittings over time, which can lead to leaks.
Does a leaking pool need to be resurfaced?
Not always. Many leaks come from equipment or plumbing. But if the finish is cracked, peeling or badly worn, resurfacing can restore the surface and stop the loss.
Should I keep filling my pool if I suspect a leak?
Keep it at a safe level, and never let it drop below the skimmer, or the pump can run dry and fail. Get the leak diagnosed quickly, since every day it runs wastes water and chemicals.
How much does pool leak repair cost in Fort Myers or Naples?
It varies widely, from a low-cost O-ring or gasket to a major plumbing or shell repair. A professional inspection is the only way to get an accurate price.