Is My Pool Leaking, or Is It Just a Texas Summer?

In a Dallas–Fort Worth August a pool can lose a noticeable amount of water to evaporation alone, and every summer people pay for leak detection they didn't need. Here's how to tell the difference yourself, first.

Short answer: Run the bucket test for 24 hours. Both levels dropping equally is evaporation. The pool dropping noticeably more than the bucket is a leak. The clearest signal of all is loss that continues through cool, humid weather, evaporation slows down, leaks don't.

How to run the bucket test

• Fill a five-gallon bucket about three-quarters with pool water.
• Set it on a step so the bucket is partly submerged, this brings the water inside to roughly pool temperature, which matters.
• Mark the level inside the bucket and the pool level outside it.
• Leave the pump running normally. Come back in 24 hours.

Both drop about equally → evaporation. The pool drops noticeably more → you have a leak.

Run it twice. Once with the equipment running and once with it off. Worse with the pump running usually points at the pressure side of the plumbing. The same either way points at the shell or the fittings.

Signs that aren't ambiguous

• Loss continuing at the same rate through cool, humid weather.
• A patch of lawn or a flowerbed near the pool that stays wet or grows faster than everything around it.
• Cracked, lifting or settling deck near one part of the pool.
• Air bubbles from the returns, or a pump that keeps losing prime.
• An auto-fill that runs far more than it used to.
• Chemical demand climbing for no reason: you're constantly topping up with fresh water.

Where pools leak

Through any of the fittings or accessories, through the plumbing, or straight through the shell. In practice the usual suspects are skimmers, return fittings, light niches, the main drain and its plumbing, underground supply and return lines, and structural cracks through the shell itself.

Why it isn't a water-bill problem

This is the part people underestimate. Repairing a leak matters not only to save water, heat and chemicals but to prevent undermining the pool's structural components. Water running through and around a shell washes out the material supporting it. Left long enough a fitting leak becomes a settlement problem, and a settlement problem becomes a structural one. The leak is cheap. What the leak does over two years is not.

Who has the hardest time spotting one

Anyone on ground that's already wet. On the lake peninsula in Rowlett, high water tables and heavy irrigation mean the usual visual cues (the soggy patch, the greener strip of lawn) simply never appear. Test the water level rather than the ground.

When to stop testing and call

If the pool is losing more than roughly a quarter inch a day in normal weather, if loss persists through cool weather, if you can see a directional crack, or if the deck near the pool has started to move. Those aren't monitoring situations.

How it gets fixed

Plenty of leaks come down to a fitting or a section of line, and that's a straightforward repair. When the source is a structural crack, the fix is our staple system every 12 inches along the fracture, followed by fiberglass laminated over the entire shell, a watertight surface rather than a patch over a joint that's still moving.

How much loss is actually normal here

Evaporation in North Texas is highly seasonal, which is exactly what makes summer diagnosis unreliable. A hot, dry, breezy August day moves far more water off an uncovered pool than a still, humid one in October. Wind matters as much as temperature, and an uncovered pool loses substantially more than a covered one.

Which is why the useful test isn't a number; it's the comparison. The bucket sits in the same air, the same sun and the same wind as the pool. Whatever evaporation is doing that day, it does to both.

Common false alarms

• Splash-out. A weekend with children in the pool moves a surprising amount of water over the coping.
• Backwashing. If you backwashed a sand filter and forgot, that's inches.
• An auto-fill that has failed closed. The pool isn't losing more than usual, it just stopped being topped up.
• A new water feature. Spillways and sheer descents increase surface area and evaporation.

What leak detection involves

The order runs cheapest-and-most-likely first: check the obvious fittings and accessories, isolate the plumbing to see whether loss changes with equipment state, then pressure-test individual lines to narrow it to a run. Only after that do we start considering the shell itself. Anyone who opens by proposing to dig has skipped several steps.

Limits

The bucket test tells you whether, not where. It also can't distinguish a plumbing leak from a shell leak on its own, which is why we run it with the equipment on and off. And a pool that's losing water fast enough to see hourly isn't a test case, call.