We get asked a lot how to properly do a water level or bucket test on a pool. The purpose of this test is first of all to determine if a pool is actually leaking and secondly to determine the amount of water it loses every day. If you’re asking why is it called “bucket test”, it is because a 5-gallon bucket is used to measure pool water loss, but also to measure the levels of evaporation we can compare to the water loss in the pool. Here in Arizona we evaporation can get up to ½ inch in the middle of the summer, so evaporation can often be confused with an actual pool leak.
If you search online you will find that there are few ways to do a bucket test, but over the years we have determined that the following method is the most precise and easiest to set up, even for a person with no pool experience.
First you want to get a clean, preferably new 5-gallon plastic bucket like the ones you can find in Home Depot or Lowes. Make sure that the bucket you will be using is free of leaks. You will also need a permanent marker- we learned that Sharpie Pro variety works the best on wet plastic. After you have all the tools you will need to turn your pool pump off if its not already off and wait for the water to settle down for about 5 minutes. Meanwhile fill up the bucket with water, you want it almost full, maybe 2-3 inches down from the top of the bucket. You can use pool water too. Set the bucket at the top walk in step inside the pool, like it is shown on the picture bellow.
There are two reason why you want to fill up the bucket almost full, first is so that the bucket doesn’t move or float easily, second is because you want wind and sun hit the water surface as much as it does rest of the pool. Only that way you will get the correct evaporation reading that can be compared to the pool water loss.
After the bucket is all set and water calms down, mark it just like it is on the picture with the tip of the arrow touching the water surface. Don’t mark it with a horizontal line, you can never mark it right that way and your Sharpie will stop working if you make it too wet. Remember you need one mark on the inside of the bucket, and one on the outside. Below are two more examples of how to set the bucket. IMPORTANT NOTE: Make sure to turn the auto-fill off.
So now that you are set up, you just need to wait a day to see the results. Keep in mind that even if you a little bit of rain it should not affect the results, since the bucket and your pool should rise up by exactly the same amount. Some people also prefer to leave the bucket in for two days, which is something you can do if the next day you’re unsure of the reading. If your pool has a small leak it will show better in the bucket test if you keep the test going for longer. Normally 24 hours is more than enough for a pool leak to show.
Just take a look at the next two photos, you will see clearly how it looks on the bucket when a pool is leaking.
You can see on this picture how it looks like when pool loses the same amount of water as the bucket, in other words pool water loss was just normal evaporation.
This is how bucket test looks like when there is a leak in the pool. As you can see in these pictures, you can clearly tell that the pool lost more water then the bucket that just lost water to evaporation. If you do a bucket test on your pool and the next day you see similar results, you will need to call a pool professional who can detect and repair pool leaks. Keep in mind that unattended pool leaks lead to high water bills and can cause structural damage to pool shell, deck or even your house, so spotting and dealing with leaks on time will save you a lot of headache and money in the long run.