How To Find A Leak In A Concrete Pool Before Atlanta Water Costs Climb

Your water bill has climbed for the second month in a row, and you are refilling your concrete pool more often than you used to. That pattern is one of the earliest and most reliable signals that your pool is losing water beyond what evaporation accounts for, and for homeowners in the Atlanta area, ignoring it only makes the repair more expensive.

Concrete pools are especially prone to leaks because the shell, plaster surface, and underground plumbing lines all shift over time as Atlanta's clay soil expands and contracts with seasonal moisture changes. 

Keep reading to learn how to work through the detection process yourself, from analyzing your water loss patterns to performing a bucket test, inspecting the shell, checking your equipment pad, and running a basic dye test. 

Start With Water Loss Patterns

Losing more than a quarter inch of water per day is a signal worth investigating. A concrete pool that drops an inch or more in 24 hours is almost certainly leaking somewhere in the shell, plumbing, or at a fitting.

Signs The Drop Is Beyond Normal Evaporation

Normal evaporation in an uncovered outdoor pool runs roughly one-quarter to one-half inch per day under typical Atlanta summer conditions. When you are losing significantly more than that, or when the water level drops noticeably overnight when evaporation slows, the loss pattern points to a structural or plumbing problem rather than weather.

Watch for these warning signs alongside the water level drop:

• You are adding water more than twice a week to maintain a normal level
  
  
• Wet or soft ground appears near the pool shell or along the equipment pad area
  
  
• Pool chemical demand has increased without a change in bather load
  
  
• You can see visible staining, efflorescence, or mineral deposits forming around fittings or steps
  
  
• The water level appears to stabilize at a specific point, which often indicates a crack or gap at that exact elevation

Any one of these can appear without the others. Taken together, they make a strong case for an active leak rather than surface evaporation.

How Atlanta Heat And Wind Can Mislead You

Atlanta summers create conditions that accelerate evaporation, making it harder to trust your eye alone. July and August regularly push afternoon temperatures into the low to mid 90s, and afternoon wind gusts across open backyards in Roswell or Marietta pull additional moisture off the pool surface throughout the day.

A pool running on a warm, windy afternoon can lose nearly three-quarters of an inch in a single day through evaporation alone. That rate can make a small but real leak look like normal seasonal loss. The only reliable way to separate the two is a controlled comparison test rather than a visual estimate.

This is exactly why the bucket test exists, and it is the next thing you should do before you inspect a single fitting or crack.

Use The Bucket Test First

The bucket test is the most practical self-check a pool owner can perform, and it produces a clear answer in about 24 hours. It works by comparing your pool's water loss rate to that of a container of the same pool water exposed to identical weather conditions, so evaporation becomes a known quantity rather than a guess.

What You Need Before You Begin

You need a standard five-gallon plastic bucket, a waterproof marker or tape, and a 24-hour window with no rain in the forecast. Turn off any auto-fill valve on the pool before you start so the system cannot quietly compensate for water loss during the test window. If your pool heater is running, turn it off as well, since heated water evaporates faster and can skew your results.

Check the current weather forecast for Marietta, Alpharetta, or wherever your pool is located. High wind days introduce extra variance. A calm, partly cloudy 24-hour stretch gives you a cleaner reading than a gusty afternoon during a heat wave, though the test still works under typical summer conditions.

How To Set Up The Comparison Correctly

Fill the bucket with pool water to about one inch from the top. Set it on the first or second pool step so it sits in the water at roughly the same level as your pool surface. This keeps both the bucket and the pool exposed to the same sun angle, wind, and ambient temperature. 

Mark the water level inside the bucket with your marker or tape, then mark the pool water level on the bucket's outside or on a nearby step using a separate piece of tape.

Let the test run for 24 hours without adding water to either the bucket or the pool. Do not run the pump during the test if you are trying to isolate whether the loss occurs when circulation is off versus when it is running. Running the pump is useful for a second round of testing to check whether loss increases when suction is active, which would point toward a plumbing or skimmer issue.

What The Results Actually Mean

After 24 hours, compare the two levels. If the pool dropped the same amount as the bucket, you are looking at normal evaporation. If the pool dropped more than the bucket, your concrete pool has a leak somewhere. The difference in inches between the two gives you a rough sense of how much water is escaping beyond what evaporation accounts for.

The bucket test confirms that a leak exists, but it cannot tell you where the leak is located. That distinction matters because the next step changes completely depending on whether you are dealing with a surface crack, a fitting failure, or a plumbing line buried beneath your deck. 

Knowing your pool is losing half an inch more than the bucket indicates it is time to start looking at the shell and fittings up close.

Inspect The Shell And Surface Closely

Concrete pool shells crack over time, and Atlanta's clay soil accelerates the process more than most pool owners expect. The ground beneath your pool shifts when heavy rains saturate the clay, then contracts again during dry stretches, and the shell absorbs that stress continuously.

Plaster Cracks And Porous Areas To Watch

Walk the full perimeter of your pool and look at the waterline tile, the plaster just below it, and the floor near the main drain. Hairline cracks that run along the tile line are worth marking with a grease pencil so you can track whether they grow. 

A crack wider than a credit card's thickness, or one with visible discoloration or rust staining around it, has likely been open long enough to allow consistent water movement.

Look for rough, pitted, or chalky plaster texture along the floor and walls, particularly in the deep end. Plaster that has degraded to the point of exposing the gunite layer beneath it can allow water to seep through the shell without a visible crack. This condition, sometimes called plaster porosity, shows up in pools with a long history of imbalanced water chemistry or in surfaces that are simply past their service life.

Steps, Lights, Skimmers, And Return Openings

The most common leak sites in concrete pools are not always visible cracks on the floor. Fittings create transition points where plaster meets plastic or metal, and those transitions crack under ground movement and seasonal thermal stress.

Inspect these specific areas carefully:

• Skimmer throat: Look for a gap between the skimmer body and the surrounding concrete or plaster. Even a thin separation here can drain water steadily.
  
  
• Return fittings: Check where the return eyeball or fitting plate meets the wall. Run your finger around the edge to feel for gaps or looseness.
  
  
• Light niches: The conduit and niche housing on a concrete pool are frequent leak sites, especially when the original bonding or sealant has aged.
  
  
• Steps and benches: The seam where steps meet the pool floor or wall is a stress concentration point, and cracks along that seam are common in older Atlanta-area pools.

If you find a suspicious area, note its location and approximate water depth so you can return to it during dye testing. Once you have mapped the shell, the next place to look is at the equipment pad outside the pool itself.

Check Equipment Pads And Exposed Fittings

Equipment-side leaks account for a significant share of water loss in concrete pools and are often the easiest to spot before calling for professional help.

Pump, Filter, And Valve Warning Clues

Walk out to your equipment pad and look at the ground around the base of the pump, filter tank, and any valves. Staining on the concrete pad, mineral deposits on pipe joints, or visibly wet soil adjacent to the pad are all signs that water is escaping somewhere in the equipment loop. 

A pump lid with a worn O-ring will drip steadily during operation. A pressure gauge that fluctuates more than usual, or a filter that loses pressure between cleaning cycles, can also indicate a plumbing-side issue.

Check the sight glass and the multiport valve on a sand or DE filter for moisture around the gasket seating. These are inexpensive parts that wear out every few years due to the sun exposure and temperature swings typical in Alpharetta or Johns Creek from April through October.

Wet Soil, Air Bubbles, And Pressure Changes

Wet or persistently damp soil between the equipment pad and the pool shell, especially in areas that stay soft even after several dry days, points toward an underground pipe leak. This is one of the most frustrating findings because the water source is invisible, yet the ground tells you something is moving beneath the surface.

Air bubbles coming from the return lines while the pump is running indicate a suction-side air intrusion, which often points to a crack or gap in the suction plumbing between the skimmer and pump. That air entry point is usually underground. 

If you have followed the equipment pad check and still cannot pin down the source, dye testing around suspect surface areas is the next tool in your diagnostic sequence.

Try Basic Dye Testing In Still Water

Dye testing is a simple, low-cost method for confirming whether water is actively moving through a specific crack or fitting. It works by releasing a small amount of colored dye near a suspected area and watching whether the dye gets drawn in, which indicates suction from water escaping through that point.

Where Dye Testing Works Best

Turn off the pump and let the water go completely still before testing. Use a pool-safe dye or food coloring in a syringe or squeeze bottle for precise placement. Red or dark blue shows up best underwater. Move slowly to avoid disturbing the water.

Release a small drop of dye six to eight inches away from the suspected crack or fitting, then stop moving. Watch for three to five seconds. If the dye drifts toward the crack and gets pulled through it, you have found an active leak site. If the dye disperses uniformly in all directions, water is not moving through that point at a meaningful rate.

Dye testing works reliably around skimmer throats, return fittings, light niches, step seams, and visible surface cracks when you already have a specific target area based on your shell inspection.

Limits Of Dye Around Hidden Plumbing

Dye testing cannot locate a leak inside buried plumbing lines. Once a pipe is beneath the pool deck or yard, there is no surface access point to introduce dye near the failure location. The dye simply disperses before it reaches any underground pipe crack or joint separation.

This is the practical boundary of every DIY detection method. If your bucket test confirms a real leak, your equipment pad check turns up nothing, and your dye test finds no active surface sites, then the leak is almost certainly in the underground plumbing. 

That specific finding requires professional pressure testing and electronic detection equipment, which is a different diagnostic category entirely.

Know When You Need Professional Leak Detection

If your bucket test indicates a real leak but your visible inspection and dye testing cannot identify the source, you are past the point where self-diagnosis can move the problem forward.

Why Pressure Testing Finds Underground Line Problems

Pressure testing works by isolating individual plumbing lines, sealing them, and introducing compressed air or water at a controlled pressure. A line that holds pressure has no active leak. A line that loses pressure has a breach somewhere along its length. 

Technicians can also use electronic listening equipment to detect the sound of water escaping through pipe walls buried beneath the deck, narrowing the dig zone to a precise location before any concrete is disturbed.

This matters because excavation without an accurate location wastes time and money. Pressure testing, combined with electronic detection, routinely identifies leak locations to within inches, keeping the repair footprint as small as possible. 

For concrete pools in Marietta or Roswell where the deck, landscaping, or hardscape are part of the outdoor living space, protecting those surfaces during a repair matters as much as fixing the leak itself.

What To Expect From a Local Inspection Visit

A professional pool leak inspection typically begins with a review of the water loss history you have already documented, including your bucket test results and any areas you marked during your shell inspection. The technician will then work through the pool shell, fittings, and equipment connections with dye testing before moving to pressure testing on the plumbing lines.

Expect the full inspection to take two to three hours on an average-sized concrete pool. You will receive a specific finding, not a general assessment, at the end of the visit. That finding tells you whether the repair is a surface issue, a fitting replacement, or an underground plumbing repair, and it shapes everything about the cost and timeline that follows.

Frequently Asked Questions

Why Is Your Concrete Pool Water Level Dropping Faster Than Normal Even When You're Not Swimming?

Increased water loss when the pool is not in use, with splash-out at zero almost always, points to an evaporation or structural leak issue rather than a usage problem. A concrete pool that drops more than a half inch overnight on a calm, moderate-temperature night should be tested with the bucket method to rule out evaporation before inspecting the shell and fittings.

Where Are the Most Common Places a Concrete Pool Leaks: Skimmer, Returns, Lights, or the Main Drain?

Skimmer throats and light niches are the two most frequently identified leak sites in aging concrete pools, followed closely by return fitting flanges and step seams. The main drain can also leak but is harder to access for visual inspection without diving gear.

How Do You Do a Simple Bucket Test To Confirm You're Losing Water To a Leak, Not Evaporation?

Fill a five-gallon bucket with pool water, place it on a submerged pool step, and mark both the inside bucket level and the pool water level on the exterior. After 24 hours with no rain and the auto-fill off, compare the two drops. A pool that drops more than the bucket has a leak beyond normal evaporation.

What Pool Leak Detection Methods Can You Use To Pinpoint a Leak Before You Call for Professional Testing?

You can perform the bucket test to confirm real water loss, conduct a close visual inspection of the shell and fittings, and use dye testing near specific suspect areas while the pump is off. These methods cover surface and fitting leaks but cannot locate underground plumbing failures.

Can You Use Dye, Leak-Finder Kits, or Sealants to Track a Leak Without Damaging Your Plaster or Tile?

Pool-safe dye is non-damaging and effective for confirming active surface leak sites when applied carefully in still water. Liquid sealants applied without professional diagnosis often mask symptoms temporarily without addressing the structural cause, and they can complicate later professional repairs by obscuring the actual failure point.

When Should You Stop Guessing and Schedule Pool Leak Detection or Underground Plumbing Repair in Atlanta, Marietta, Roswell, Alpharetta, or Johns Creek?

If your bucket test confirms a leak, your visible inspection finds nothing obvious, and your dye test comes up empty, the source is almost certainly underground and requires professional pool leak detection using pressure-testing equipment. At that point, continuing to self-diagnose costs time while the water loss and potential soil erosion continue.

Take The Guesswork Out Of Your Concrete Pool Leak

Watching your water level drop week after week without knowing why is frustrating, and it gets more expensive the longer the source stays unidentified. The steps in this guide give you a clear picture of what your concrete pool is telling you before anyone sets foot in your yard.

When those steps point to an underground plumbing problem, or when the surface inspection turns up cracks that need professional repair, self-diagnosis has taken you as far as it can. That is the moment to bring in someone with the equipment and experience to locate the leak precisely and fix it the right way.

Atlanta Leak Pros serves Marietta, Roswell, Alpharetta, and Johns Creek with in-house leak detection, concrete pool crack repair, and full pool renovation. Call today and get a free estimate on your pool leak repair or renovation.