The rate of evaporation can vary daily because it of a variety of environmental and pool related conditions such as wind, water temperature, dew point, and barometric pressure. Before determining whether or not your pool has a leak, you can perform a simple test called The Bucket Test to see what is causing the water loss. The Bucket Test exposes water in a bucket to the same conditions as those affecting your pool water. By comparing the water loss in each, you can determine whether your pool has leak or if the loss of water is caused by evaporation.
Bucket Test Procedure:
- Make sure the pool water is at its normal level.
- Fill an empty bucket with pool water until there is 1 inch left to the top of bucket. By doing this you are making sure that the air movement over both surfaces is the same.
- Place the bucket on the first or second step of the pool. This ensures that the temperature in the bucket is the same as the pool water’s. It may be necessary to place bricks or rocks in the bucket to keep it from floating away.
- Mark the water level inside the bucket.
- Mark the water level of the pool on the outside of the bucket, on the pool wall, or skimmer face plate.
- Operate the pool for 24 hours as it had been operated when a leak was first suspected.
- Compare the two levels. If the pool water level is lower than the bucket water level, there is probably a leak.
Calculating the Gallons of Water Lost
To determine the amount of a leak it is helpful to translate inches of water lost into gallons of water leaking. First subtract the bucket water level from the pool water level, leaving the inches of water lost. Next calculate the square footage of the water surface of your pool. Enter these results into the following equation:
Inches of water lost x Area of Pool Surface (in square feet) x .62 gallons
You can translate this number into gallons of water lost per hour or per minute. You may also find it helpful to calculate how much you are spending on chemicals or on water to replace the water that has leaked from the pool.
Establishing suspected leak locations with a “Pump on / Pump off test”
Comparing the results of successive bucket tests with the pump on for 24 hours to the results with the pump off for 24 hours can provide information on the location of the leak.
Water loss pump on > water loss pump off = return plumbing leaks (pressure side plumbing)
Water loss pump on < water loss pump off = skimmer/main drain plumbing leaks (suction side plumbing)
Water loss pump on = Water loss pump off = shell, liner or fitting leaks (non-plumbing)
Although these are not always accurate due to varying environmental conditions during the tests, the information they provide can establish potential locations to begin your leak search. You can provide this information to a leak professional which will help them to efficiently solve your pool leak problem.