We often get phone calls from people asking if the water loss in their pool is from a leak. Water loss is always going to occur due to evaporation. Many factors effect how much evaporation takes place, such as sunlight, wind, barometric pressure, and the amount of activity in the swimming pool. There’s a simple way to determine if water loss is from a potential leak or evaporation. Here are the steps to follow:

1. Fill the pool to the normal fill level. Fill a 5 gallon bucket with pool water, until it is about 5 inches from the top.

2. Immerse the bucket, at least 5 inches in the water on a stable step or bench of the pool. Mark the water level inside the bucket with a sharpie marker or duct tape.

3. Turn off the pump and mark the pool water level on the outside of the bucket with marker or duct tape. Once complete, turn the pump back on and resume normal operation.

4. After 24 hours, but no more that that, compare the two water levels. If the water level in the pool goes down more than the water level in the bucket, there is likely a leak in the pool. If the water levels are about the same, it is likely due to evaporation.

5. Perform the test a second time to confirm results.

Water loss on average, in a typical swimming pool, is about 1/4″ a day, but can very depending on your weather conditions and the amount of direct sunlight. A Pool Cover can significantly reduce water loss due to evaporation.

Remember, if you suspect a leak, it does not mean that the pool shell is compromised, it could be due to pool plumbing. Although, you should expect about 1/4″ of evaporation a day, it could be as much as 1/2″, but anything more than that is likely a leak. You will need to call a swimming pool service company or leak detection specialist to determine the cause.