Normally, pool water evaporation is about 1″ to 2½″ per week. To determine if you have a leak, you can perform a simple bucket test using an ordinary plastic bucket:

  1. Bring pool water to normal level (middle of skimmer).
  2. Place a bucket on the first or second step of the pool.
  3. Fill the bucket with pool water to the same level as the pool.
  4. Mark the water level on the inside of the bucket.
  5. Shut off the pump and mark the pool water level on the outside of the bucket.
  6. Resume normal pump operation.
  7. After 24 to 48 hours, compare the two water levels:
    • If the pool water level (outside mark) goes down more than the water level inside the bucket, you probably have a leak.
    • In case of rain, repeat the test (be sure that your pool is equipped with an auto-fill to shut off the water supply).

Test is invalid after 48 hours.