Evaporation is dependent on a variety of environmental and pool related conditions, (wind, water temp, dew point, barometric pressure, and other to a lesser extent). Because of this the evaporation rate can vary greatly from day to day and even pool to pool.
Before becoming too concerned about a leak you can do a simple test to determine if water loss in your swimming pool is due to a leak or just evaporation. This simple test is called the bucket test.
Basically, the bucket test exposes water in a bucket to the same conditions as those affecting your swimming pool. By comparing the water loss in each, it is possible to determine if the pool is leaking or if supposed leaks are just the result of water being lost to the air.
The Bucket Test Procedure
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 the bucket. (By filling the bucket close to the top you are 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 few bricks or rocks into the bucket. (By placing the bucket in the pool water you are ensuring that the water temperature of each will be similar)
4.Mark the water level inside the bucket.
5.Mark the water level on the outside of the bucket, on the pool wall, or skimmer face plate.
6.Operate the pool WITH PUMP ON for 24 hours
7.After 24 hours, compare the two levels of water in the bucket & in the pool. If the pool water (outside mark) goes down more than the inside water level, there is probably a leak.
8.REPEAT the same test with the PUMP OFF for 24 hrs and record the results
9.Call/fax/email the results to Backyard Getaways.
NOTE: this test cannot be done if rain occurs in the 24hr. period. If it rains, it must be re-done. Also, make sure that the conditions of the pool are EXACTLY the same for both tests (ie. that if the solar cover is left on, it is left on for both tests etc.)
Calculating the gallons of water lost from your pool
To more effectively visualize the leak or leaks you have it will be helpful to translate inches of water lost into gallons of water leaking. First subtract the bucket loss from the pool loss. The result will be inches of water lost due to leaks. Next calculate the square footage of the water surface of your pool. Then enter these results into the following equation:
Inches of water lost x Area of Pool Surface (in square feet) x .62 gallons
Visualizing the actual size of your leak is easier and as you can now translate this number into gallons of water lost per hour or per minute. You may also find it valuable to calculate how much you are spending on chemicals or for that matter water to retreat or replace the water that has leaked from the pool.
Establishing suspected leak locations with a “PUMP ON/PUMP OFF” test
Comparing the results of subsequent bucket tests with the pump on for 24 hours to the results with the pump off for 24 hours can provide additional information on the leak’s location.
1.Water loss pump on > water loss pump off = suspect return plumbing leaks (Pressure side plumbing)
2.Water loss pump on < water loss pump off = suspect skimmer/main drain plumbing leaks, (Suction side plumbing)
Water loss pump on = Water loss pump off = suspect shell, liner or fitting leaks, (non-plumbing)
Although these tests are prone to false results because of varying environmental conditions during the tests, the information they provide can at least establish suspect locations to begin your leak search.