A pool that's losing water isn't always obvious. Sometimes it announces itself with a cracked deck or a soggy patch of yard. Other times it hides behind a water bill that just keeps creeping up, month after month, with no clear explanation. Either way, the earlier you catch a leak, the less it costs you — in water, in repairs, and in peace of mind.

Here in the Triangle, Rising Sun Pools has been building and servicing pools since 1972, which means we've chased down just about every kind of leak a pool can develop. Below is what we tell homeowners who call us worried something's wrong.

Know the Warning Signs

Every pool loses a little water naturally. The question is whether what you're seeing goes beyond that. A few things worth paying attention to:
Your water bill jumps noticeably without a clear reason.
You're topping off the pool far more often than usual.
The ground around the pool equipment or shell stays damp or soggy even when it hasn't rained.
Algae keeps coming back no matter how consistently you balance and treat the water — often a sign that fresh, untreated water is seeping in from somewhere and throwing off your chemistry.
You notice air bubbles sputtering out of the return jets, which can point to a suction-side leak pulling air into the system.
And cracks — in the pool shell, the tile line, or the surrounding deck — are never something to ignore, even small ones.

None of these guarantee a leak on their own. But if you're seeing more than one, it's worth digging deeper before assuming it's just a hot summer and a thirsty pool.

Rule Out Normal Evaporation First

Before you panic, it's worth ruling out the simplest explanation: evaporation. On a hot, windy day, a pool can lose up to a quarter inch of water — sometimes more, depending on temperature, humidity, and how much wind is moving across the surface. That's completely normal and not something you need to fix.

The easiest way to tell the difference is the bucket test, and you can do it yourself in about 24 hours:

Turn off your autofill valve, pool pump, sweeps, and any water features. Set a 3-5 gallon bucket on one of the top steps of the pool and fill it about two-thirds to three-quarters full. Mark the water level inside the bucket and the water level of the pool itself, right next to it, with a waterproof marker or a strip of tape. Note the time, then leave it alone for a full day.

Come back 24 hours later and compare. If the pool's water level dropped noticeably more than the level inside the bucket, that's a strong sign you've got an actual leak — the bucket only loses water to evaporation, so anything beyond that gap in the pool points to something else. If both dropped by roughly the same amount, you're most likely just seeing normal evaporation, and there's nothing to worry about. Running the test for two or three consecutive days tends to give you a clearer, more reliable answer.

Try the Tape Test, Too

If you want a second way to confirm what the bucket test told you — or you'd rather skip the bucket altogether — the tape test works off the same basic idea, just applied to the whole pool.

Start with the pool filled to its normal operating level, and shut off all the equipment, including any timers or automated systems that might kick the pump back on during the test. Use a strip of painter's tape or a grease pencil to mark exactly where the water sits. Then leave it alone for 24 hours.

When you check back, measure the gap between your original mark and the new water line. A drop of more than about a quarter inch is more than you'd expect from evaporation alone, and it's usually worth following up with a dye test to narrow down where the water is actually going. Common trouble spots include skimmers, return lines, light fixtures, drains, and hairline cracks in the shell.

There's a useful second half to this test, too, once you've refilled the pool back to normal level. This time, mark the water level again, but instead of leaving the equipment off, run the pump and filter continuously for a full 24 hours before checking the mark. If the water loss is significantly worse with the equipment running than it was with it off, that's a strong signal the leak is somewhere in the plumbing rather than the pool shell itself, which helps a technician know where to start looking.

One caution here: don't let the water level drop below the skimmer during either round of testing, since that can damage your equipment. If the level starts dropping fast, stop the test, jot down how much water was lost and how long the equipment ran, and call in a professional from there.

Understand the Common Causes

Leaks tend to come from a handful of usual suspects. Plumbing lines can crack or come loose underground, particularly in older pools or ones that have shifted slightly with the soil. Seals and gaskets around lights, skimmers, and returns wear out over time and start letting water past. The pool shell itself can develop structural cracks, especially in older gunite or concrete pools. Equipment — pumps, filters, heaters — can develop small leaks of their own that have nothing to do with the pool structure. And expansion joints, the flexible material where the deck meets the pool, tend to deteriorate with age and weather, opening a path for water to escape unnoticed.

Know When to Call a Professional

A DIY bucket test is a great first step, but it can only tell you that a leak exists — not exactly where it's coming from. If your water loss is significant, if you can see cracking or structural damage, or if you've run the test and still can't pin down the source, it's time to bring in a professional.

Locating a leak often requires specialized tools — dye testing, pressure testing the plumbing lines, or, in trickier cases, underwater inspection. Chasing a hidden leak without the right equipment usually means guessing, and guessing wrong can mean digging in the wrong spot or missing the actual problem entirely.

Don't Wait to Make the Repair

A small leak rarely stays small. Left alone, it can undermine the deck, erode the soil around the pool shell, damage landscaping, and slowly drive up your water bill month after month. Catching it early is almost always cheaper and simpler than waiting until it forces a bigger repair.

If you've run the bucket test and suspect a leak, or you'd rather skip straight to a professional evaluation, Rising Sun Pools has spent over 50 years helping Triangle-area homeowners track down and fix exactly this kind of problem. Get in touch and we'll help you figure out what's really going on before it turns into something bigger.