How to test if your pool is leaking

So, you're filling your pool more often than normal. Is it a leak? And where's it coming from? In this article we cover three basic leak tests. The "bucket test" will tell you if a drop in your pool water level is due to evaporation or a leak. The liner test will let you know if your liner's sprung a leak. The third test will let you know if the leak is in your equipment or lines.

TEST #1 The bucket test

  • 1 Bring the pool water to its normal level.
  • 2 Fill an empty bucket with pool water to about one inch from the top of bucket. (By filling the bucket close to the top you're ensuring that air movement over the surface of the bucket will be similar to that of the pool.)
  • 3 Place the bucket on the first or second step of the pool. (To keep it from floating away it may be necessary to place a brick or a few rocks into the bucket.) By placing the bucket in the pool water you're ensuring that the water temperature of each will be similar.
  • 4 Mark the water level inside the bucket.
  • 5 Mark the water level of the pool on the outside of the bucket.
  • 6 Operate the pool for 24 hours in the same way it was operating when a leak was first suspected.
  • 7 After 24 hours, compare the water levels in the pool and the bucket to the marks you made on the bucket. If the pool water level has dropped more than the bucket water level, there's probably a leak.


  • 1 Perform a bucket test (see test #1 for details) to get baseline information on how fast you're losing water in your pool.
  • 2 Turn the pool equipment off completely and leave it off for the remainder of the test.
  • 3 Remove the pool return jets and install the winter plugs. Remove the skimmer basket and install the gizzmo and/or winterizing plug/plugs in the hole/holes in the skimmer. This step is to isolate all water connections from the pool to the equipment and lines.
  • 4 Complete a second bucket test. If the water level in the pool drops at the same rate as the baseline bucket test, then the water loss is from the pool. The leak could be caused by a small nick or tear in the liner, or one of the seals around a return, a light or the skimmer may have failed. If the water loss in the pool is less than the baseline bucket test, then the issue is in the lines or equipment, and you should perform test #3.

TEST #3 The equipment connections test

  • 1 If you have a sand filter, check the waste or backwash line to see if any water is escaping when the filter is set to filtration. If you see water, then a new filter head, filter head gasket, key assembly or other repair is probably required.
  • 2 Check the filter drain plugs, pump drain plugs and all connections after the pump. Check under the heater (if applicable) to see if water is leaking from underneath the heater. Check in and around the chlorinator to see if any water is visible. Repair leaks as required.
  • 3 If no leaks are found at the backwash line or at the equipment, consult Buds for options.

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