Florida pools lose about 1/8 to 1/4 inch of water a day to evaporation. The bucket test shows whether you’re losing more than that: the bucket sits in the same sun, wind and heat as your pool, so it evaporates at the same rate. If the pool drops more than the bucket, the difference is a leak.
How to do the pool bucket test, step by step.
Before you start: turn off any auto-fill, and leave the pump on its normal schedule.
- Fill the pool to the middle of the tile.
- Fill a bucket with pool water to about 1 inch from the top.
- Set the bucket on the first step of the pool.Sitting partly in the water keeps it at the same temperature as the pool.
- Use a pencil to mark the water level inside the bucket.
- Mark the pool’s water level on the tile or the skimmer.
- Wait 24 hours.Don’t swim, add water or move the bucket.
- Compare each water level to its pencil mark.
Reading your bucket test result.
✓ About the same drop
Both went down by about the same amount. That’s normal evaporation — no leak.
! The pool dropped more
You likely have a leak. The difference between the two is roughly what you’re losing each day.
Bucket dropped more than the pool? Something interfered — it may have sat in different sun, tipped, or been marked a little off. Run the test again.
How much water is that?
Normal evaporation runs about 1/8 to 1/4 inch a day, a little more on windy days or when the water is much warmer than the air. Losing a full inch a day is almost always a leak — and on an average pool that’s about 400 gallons a day, or 12,000 a month.
| Pool size | Water in 1 inch |
|---|---|
| 15 × 30 ft | About 280 gallons |
| 16 × 32 ft | About 320 gallons |
| 18 × 36 ft | About 400 gallons |
| 20 × 40 ft | About 500 gallons |
For a rectangular pool: length × width × 0.62 gallons per inch; freeform pools run about 75–80% of that. Or let our Water Loss Calculator do the math.
Pool losing water? When evaporation looks like a leak.
Some changes make a pool evaporate faster, and that extra loss is easy to mistake for a leak. If the water started dropping faster after one of these, run the bucket test before assuming the worst:
- A new heater. Heated water can double evaporation.
- A damaged or removed screen enclosure. More wind and sun can double the loss.
- A new waterfall, spillover or deck jets. Moving water puts more of it in the air.
- A change of season. Cool, dry, windy weather pulls water off a warm pool fast.
- Heavy use. A full house of swimmers splashes out a lot — common with vacation rentals.
Tips for an accurate test.
- Keep the bucket in the same sun or shade as most of the pool.
- Run waterfalls, spa spillovers and timers on their normal schedule.
- A difference under 1/16 inch is within pencil-mark error.
- Some leaks only show under certain conditions — pump on, heater running, spa spilling over. If your results are unclear, run the test again.
Confirmed a leak? These clues help us find it.
Call sooner rather than later: escaping water washes out the soil around a pool and turns a simple repair into a bigger one. Before your visit, notice when the pool loses water:
Only when the pump runs
Often equipment: a valve or filter fitting, solar panels, or an attached spa pushing water up to a crack.
Only when the pump is off
Often a broken suction pipe, or an attached spa draining back over a fitting.
The same either way
Usually the pool itself: shell or bond beam cracks, a light, a skimmer, or gaps around fittings.
It stops at a certain level
The leak is likely at that height — the bottom of the tile line or the skimmer opening, for example.
Don’t let the pool drain to find that level. If the water drops below the groundwater outside the shell, it can push the pool up out of the ground. Keep it topped off and clean until we arrive. And if it stopped dropping on its own, the leak is usually still there — the water is just below it now.
Still not sure?
A diagnostic visit settles it.
When the bucket test is unclear or you see other warning signs, a specialist visit gives you the answer. Residential diagnostic starts at $360 and produces a written finding.