What is a Bucket Test?

Leaks Downunder • November 17, 2025

If you think your pool is losing more water than it should, a simple “bucket test” is one of the easiest ways to check. You don’t need any special tools—just a plastic bucket, a marker and a day or two of patience. The bucket test helps you tell the difference between normal evaporation and a genuine pool leak.

What is a Bucket Test?

A bucket test is a basic DIY check for pool or spa leaks. It works by comparing how much water your pool loses over 24–48 hours with how much water evaporates from a bucket of water sitting beside (or partly in) the pool. Because the bucket is exposed to the same sun, wind and air temperature as your pool, it acts as a reference for natural evaporation.


  • If both the bucket and the pool drop by roughly the same amount, it’s probably just evaporation.
  • If the pool drops significantly more than the bucket, that’s a strong sign you’ve got a leak.

How to Do a Bucket Test (Step-By-Step)

  1. Turn off any auto top-up systems

    If your pool automatically refills, switch that feature off. You need to see real water loss without fresh water being added.
  2. Set your normal water level

    Make sure the pool is at its usual operating level (often halfway up the skimmer opening).
  3. Position and fill the bucket
    Place a plastic bucket on a pool step or ledge so the top stays above water. Fill it with pool water until the water level inside the bucket matches the water level outside.
  4. Mark both water levels
    Use a waterproof marker or tape to mark: The water level inside the bucket and the pool water level on the inside of the skimmer or on a nearby tile
  5. Run the test (no swimming)
    Leave the pool for 24 hours with: No one swimming; no backwashing, vacuuming or splashing; water features turned off. You can do the test with the pump on or off, but keep it the same for the whole period.
  6. Check the results

    After 24 hours, compare how far the water dropped in the pool versus the bucket. A ruler or tape measure makes this easier.
  7. Optional: repeat with different pump settings

    If you want more clues: Do one test with the pump off; do another with the pump running. Differences between the two can help indicate whether the leak is in the plumbing or the pool structure.

How to Interpret a Bucket Test

  • Pool and bucket drop the same amount

    This usually means the loss is normal evaporation for your climate and conditions.
  • Pool drops more than the bucket

    This points to a leak. The greater the difference, the more serious the leak may be.
  • Pool loses more water when the pump is on

    The leak could be in the circulation system – pipes, filter, heater, chlorinator or other equipment.
  • Pool loses the same (extra) amount with pump on and off

    The leak is more likely in the pool shell, skimmer box, around lights or fittings.

What a Bucket Test Can’t Tell You

A bucket test is a great starting point, but it has limits:


  • It won’t show the exact location of the leak
  • Sudden weather changes, rain or splashing can affect results
  • Very small leaks might be hard to detect in a short test


That’s why pool owners often use the bucket test as a first check. If the pool is clearly dropping faster than the bucket, the next step is to call a professional leak detection specialist. They can use tools like pressure testing, dye tests and acoustic listening equipment to accurately locate the problem and recommend the right repair.


By spending a day on a simple bucket test, you can rule out normal evaporation, confirm whether a leak is likely, and decide if it’s time to get professional help before the problem becomes more costly.

Think You Might Have a Pool Leak?

If your bucket test shows your pool water level is dropping faster than it should, it’s time to get it checked properly. At Leaks Downunder, we specialise in finding and fixing pool leaks for homeowners across Moreton Bay, Brisbane and the Sunshine Coast.


As licensed plumbers and pool leak detection specialists, we use professional equipment to accurately locate leaks in pipes, fittings and pool structures—and in most cases, we can also carry out the repair for you, saving you the hassle of dealing with multiple trades.


Don’t let a small leak turn into major damage or crazy water bills. Call Leaks Downunder on 0410 862 034.