The bucket test tells evaporation apart from a real leak in 24 hours. Set a bucket on a pool step, fill it to match the pool level, and mark both water lines. If pool and bucket drop the same amount, it is evaporation. If the pool drops more, water is leaking out and it is time for electronic leak detection.
What you need
A 5-gallon bucket, a piece of tape or a waterproof marker, and 24 hours when nobody will swim. That is the whole equipment list.
The 24-hour bucket test
- Place the bucket on a pool step. Set it on the first or second step so it sits stable with the rim above the waterline. Fill the bucket with pool water to roughly the same level as the pool around it.
- Mark both water lines. Put tape on the inside of the bucket at the bucket's water level, and tape on the outside of the bucket (or the pool wall) at the pool's water level. Turn the pump off for the test period if you can. It removes a variable.
- Wait 24 hours. No swimming, no backwashing, no auto-fill running. Normal weather is fine; just note if it was unusually hot or windy.
- Measure both drops. Compare how far each line fell. Same drop in bucket and pool means evaporation. Pool dropped more than the bucket means water is leaving the pool through a leak.
Reading the result
Equal drop. Evaporation. In a hot, windy Sacramento summer week, pools can lose a quarter inch a day or more to evaporation alone. A pool cover cuts this dramatically.
Pool dropped more. Leak. The difference is water escaping through the shell, fittings, skimmer, or underground plumbing. Note roughly how much extra the pool lost per day. A technician will ask.
Bucket dropped more. Re-test. Something is off, usually splash-out or the bucket getting bumped. Run it again on a calm day.
What speeds up evaporation
- Heat and sun. July and August in the Sacramento Valley evaporate far more than winter months.
- Wind. A breezy day can double evaporation versus still air.
- Water features. Waterfalls, spillovers, and aerators expose more surface area to air.
- Heated water. A warm spa or heated pool evaporates faster than an unheated one.
When to call for electronic detection
Call when the bucket test says leak, or when you are losing more than about a quarter inch a day with no clear cause. Electronic pool detection. Pressure-testing the lines, acoustic listening, and dye testing around fittings. Finds whether it is plumbing, the skimmer throat, a light niche, or the shell itself, without draining the pool. Pool leak detection from AquaTrace Leak Detection: (123) 456-7890.
Frequently asked questions
How much water loss is normal for a pool?
Up to about a quarter inch per day in hot, dry, windy weather is normal evaporation in this region. Consistently more than that. Or any loss in cool, calm weather. Deserves the bucket test.
Should the pump be on or off during the bucket test?
Off is better if you can manage 24 hours without it. A running pump adds variables: backwash cycles, splashing at returns, and autofill valves can all skew the comparison.
Can I do the bucket test in winter?
Yes, and winter is actually the clearest test. Evaporation is low, so any meaningful drop points strongly at a leak. Just keep the pool chemistry balanced while the pump is off.
My pool loses water only when the pump runs. What does that mean?
That points to the pressure side of the plumbing. A return line or equipment-pad leak that only flows under pump pressure. Mention this to the technician; it narrows the search immediately.
Will finding a pool leak require draining the pool?
Usually not. Electronic detection. Line pressure tests, acoustic listening, and dye checks. Is done with the pool full. Draining is a last resort, not a first step.
Related
Think you have a leak?
Call AquaTrace Leak Detection to describe what you are seeing in Citrus Heights and get a plan to find it.
Call (123) 456-7890Last updated: October 25, 2026.