Is my pool leaking, or is that just a Texas summer?
Half an inch a day is ordinary evaporation for a North Texas pool in midsummer, and roughly half the pools we are called out to for losing water are doing exactly that. The bucket test tells the two apart in 24 hours and costs nothing.
Run the test, put both measurements in, and this converts inches into gallons a day and dollars a month. If your pool is fine, it will say so.
Depth is not needed. Water leaves off the surface, so only the surface area matters.
What the test measured
Sit a bucket of pool water on a step so it is submerged to the same level inside and out, mark both waterlines, leave the pump on its normal schedule, and come back in 24 hours. Then measure how far each one fell.
Measure at the tile line, to the nearest eighth.
This is your weather, measured rather than assumed.
24 hours works. 48 is a better signal.
On your city water bill, in the upper tier for summer.
Switch the autofill off before you start. An autofill valve is the single most common reason a real leak goes unnoticed for a season: it keeps the level looking perfect and moves the entire problem onto the water bill, where nobody is watching for it.
A normal pool this size loses
160gallons a day
The test itself
Six steps, one bucket, 24 hours
Switch the autofill off
If the pool has an autofill valve, close it. Leaving it on is the single most common reason a real leak goes unnoticed for a season: it keeps the water level looking perfect and moves the whole problem onto the water bill.
Fill a bucket with pool water
Use a plain five-gallon bucket and fill it about three quarters full with water from the pool, so it starts at the same temperature.
Stand it on a step
Put the bucket on the first or second step so it is submerged, and add or pour off water until the level inside the bucket matches the level of the pool outside it. Both bodies of water now sit in the same sun, wind and humidity.
Mark both waterlines
Mark the water level inside the bucket and outside it, on the bucket wall, with tape or a grease pencil. One mark on each side.
Leave it 24 hours
Run the pump on its normal schedule and keep everyone out of the pool. Nobody swimming, no backwashing, no topping up.
Measure both drops
Measure how far the level fell inside the bucket and how far it fell outside, to the nearest eighth of an inch. The bucket is your weather, measured rather than assumed. Anything the pool lost beyond it went somewhere else.
Questions we get asked
- How much water loss is normal for a pool in North Texas?
- About half an inch a day in a North Texas summer, with nothing wrong at all. The quarter-inch rule of thumb that circulates online comes from milder conditions than ours and understates summer here by half, which is exactly how a healthy pool gets diagnosed as a leak. On a 15 by 30 foot pool, half an inch a day is roughly 140 gallons, or close to a thousand gallons a week.
- How does the bucket test work?
- The bucket sits in the same sun, wind and humidity as the pool, so whatever it loses is evaporation. Whatever the pool loses beyond that is water going somewhere other than the sky. It costs nothing, takes 24 hours, and is the only way to separate the two without instruments.
- The pool and bucket dropped by different amounts but only slightly. Is that a leak?
- Probably not. Splash-out, a windy day, backwashing, and a bucket catching slightly more sun than the pool all land in that difference. Under about an eighth of an inch a day is inside the noise. A quarter of an inch a day above evaporation is not, and on a normal pool that is thousands of gallons a month.
- Does it matter whether the pump is running?
- For the test itself, run the pump as you normally would. But if you already suspect a leak, running the test twice, once with the pump on and once with it off, narrows it down usefully: loss that stops when the pump stops is usually pressure-side plumbing, while loss that continues regardless points more often to the shell, the skimmer throat, or a light niche.
- My water bill jumped but the pool level looks fine. What does that mean?
- That is the autofill doing its job and hiding the problem. A pool with an autofill valve never looks like it is losing water, because it is being topped up continuously. The bill is the only place the loss shows up, which is why a summer water bill that jumps sharply is worth a bucket test rather than a shrug.
- Why does a small leak matter if the water is cheap?
- Because water is the cheapest thing going through the hole. Chemistry leaves at the same rate, and so does heat if the pool is heated. In Collin County there is a third reason: expansive clay soil moves a great deal with moisture, so water escaping behind a wall or under the deck does not stay a plumbing problem for long.
Free tools
The rest of the arithmetic
What does a pool really cost to own here?
All five lines, not just the service rate: electricity, water, chemicals, filter cleaning, and the replacement reserve nobody puts on a quote. Prices your pool both ways, doing it yourself and having it done.
Price my poolHow long should the pump run, and what is that costing?
Turns your pool's volume and your pump into a run schedule and a monthly electricity figure, then shows what a variable-speed pump would save and how long it would take to pay for itself.
Work out my run timeWhat do I add, how much, and in what order?
Enter what your test kit read and get an ordered correction plan with real doses for your volume. Alkalinity before pH, sanitizer last, and never two things that should not meet.
Balance my waterHow many gallons is my pool?
Measure three things and get your volume, the surface area, and what one adjustment costs at that size. Every other calculator here starts with this number.
Measure my pool