How do I know if my pool has a leak?

Comparing your water bill from the same month in the previous year, or if there is a sharp increase in your water bill from the previous month(s), is the simplest way to determine if there is a leak. You may also consider placing a piece of painter’s tape at the water level and waiting a week. If the autofill is turned off and no water has been, but the distance between the painter’s tape and the water level has increased, you may have a leak.