Anyone who has ever worked in swimming pool leak detection knows that pool leaks are sometimes just evaporation that the pool owner mistakenly believes to be an active leak. The first step in leak testing any swimming pool is to figure out if the pool is actually leaking. A surprising amount of "pool leaks" are actually just periods where the water is evaporating quickly due to environmental conditions. If you are new to owning a pool then you will not be familiar with evaporation rates or what you should consider as normal evaporation rates for your pool. The actual amount of water that your pool will lose to evaporation will be unique to your pool. Factors such as your geographic location, ambient temperature, water temperature, direct sunlight and cross winds will all have an effect on your evaporation rates as will whether you use a solar blanket cover at night.


I can tell you that in our geographic area of new jersey about 1/8" or just slightly higher (rare occasion of 1/4 inch depending on location)  of water loss per day would be normal however this is not helpful to you. You may live in an area with much higher rates of evaporation. This is why the bucket test is used to determine if a pool is leaking or if the pool is simply losing water through evaporation. The reason why the bucket test is so important is that is removes the external factors that make your evaporation rates unique. The bucket test allows you to measure the rate of water loss in your pool versus the rate of evaporation in your pool. This is the first test that every pool owner with a suspected leak should do. If you are getting inconclusive results with your test then something as simple as knowing the temperature from one day to the next can help you to accurately interpret the results of your tests.