The easiest way to calculate water loss is with a bucket test.

1. Fill up pool to normal level;

2. Fill a plastic bucket full enough so that the distance from the top of the bucket to the water in the bucket is approximately the same as the distance between the top of your pool to the water in your pool;

3. Place the bucket on a pool step

4. Using duct tape or a pencil, mark the outside of the bucket to show where the pool water level is (see image to the right);

5. Using duct tape or a pencil, mark the inside of the bucket to show where the bucket water level is (see image to the right);

6. Leave the pool untouched and unused for 24 hours. If there is rain during the test restart on a normal day;

7. Measure the distance of the outside marker to the pool water level, and the distance from the inside marker to the bucket water level;

8. If there is no leak in the pool, the distances will be the same, as it is due to evaporation;

9. If there is a difference between the two measurements, this means that you have a leak;

You can also check your expected daily evaporation at the following site: Perth, WA Bureau of Meteorology