In a Flower Mound summer, a pool can lose a noticeable amount of water to evaporation alone. But pools also develop leaks in skimmers, return lines, and fittings, and the two look identical from the deck. Before you call anyone, run the test below. It takes a day and costs nothing.
How much water does a pool normally lose to evaporation?
Evaporation depends on heat, wind, humidity, and how much the pool is used. Hot, dry, windy days pull the most water from the surface. Splashing and backwashing add to the loss. What matters for diagnosis is not the absolute amount but whether the loss is consistent with evaporation or clearly beyond it.
That is what the bucket test answers. It isolates evaporation from leaking by comparing your pool's water loss against a control sample sitting in the same conditions.
How do I run the bucket test, step by step?
You need a 5-gallon bucket, a marker or tape, and about 24 hours.
- Fill the bucket with pool water to about two-thirds full.
- Place it on a pool step so the bucket sits in the pool water, with the water level inside the bucket roughly matching the pool's water level outside it. If your steps do not allow this, set the bucket on the deck right next to the pool.
- Mark the water level inside the bucket and the water level of the pool on the outside of the bucket (or on the pool tile with tape). Mark both precisely.
- Run the pool normally for 24 hours. Keep the pump on its usual schedule so conditions match a typical day.
- Compare the marks. Measure how far each level dropped.
Reading the results:
- If the pool and the bucket dropped by about the same amount, the loss is evaporation. No leak.
- If the pool dropped noticeably more than the bucket, water is leaving the pool through a leak.
Run the test during a calm stretch of weather if you can, and avoid testing right after heavy rain or a backwash cycle, which throw off the comparison.
What if the bucket test shows a leak? What do I check next?
A positive bucket test means water is escaping somewhere. The common spots, in general terms, are:
- The skimmer. The seal where the skimmer meets the pool wall can separate over time, especially with ground movement. Look for cracks or gaps around the skimmer mouth.
- Return fittings and lights. The seals around return jets and underwater lights can fail. Check for loose fittings or deteriorated gaskets.
- The equipment pad. Walk around the pump, filter, and heater while the system runs. Look and listen for drips, and check the ground for wet spots that never dry.
- Underground lines. If everything visible looks fine, the leak may be in the buried suction or return lines. Wet or sunken areas between the pool and the equipment pad are clues.
Do a visual pass first, then check the equipment pad with the system running. Many pool leaks are found at these accessible points without any special equipment.
Can I tell whether the leak is in the plumbing or the pool shell?
A simple follow-up test helps. Mark the water level, turn the pump off for 24 hours, and mark it again. Then compare:
- Loses water with the pump on, stops with it off: the leak is probably in the pressurized plumbing (returns, equipment) that only leaks under pressure.
- Loses water with the pump off too: the leak is probably in the pool shell, skimmer, or a suction line, somewhere water escapes by gravity alone.
- Stops leaking at a certain level: note where it stops. The leak is likely at or just above that waterline, which narrows the search to fittings at that height.
Write down your results. If you end up calling a specialist, this information saves them time.
When should I call a leak detection specialist for my pool?
Call when the bucket test confirms a leak and your own checks have not found it, or when the signs point to buried lines you cannot inspect yourself. A specialist uses pressure testing on individual pool lines and acoustic listening to pinpoint underground leaks without digging up the whole deck.
Also call if the pool is losing water fast. A rapid drop can undermine the ground around the pool shell, and the longer it runs, the more the repair area grows. Our pool leak detection service covers exactly this situation.
One more case: if you are buying a home with a pool in Flower Mound, a bucket test during the inspection period is cheap insurance. Pool leaks are easy for sellers to miss and expensive for buyers to inherit.