Detecting a Leak To determine whether there is a leak in your home, use your meter. It displays the amount of water being used in real time, either in gallons or cubic metres. Make a note of the rolling counter number displayed on your reader before you go to bed or leave for work—i.e., when you will not be using any water for several hours. In the morning or when you get home from work, read the meter again before using the toilet, taking a shower, etc. Compare the two readings: If the numbers are the same, there is no leak. If the two numbers are different, that means water must have been used between the first and second reading. This is likely due to a leak. All you have to do now is determine its source. Detection of a Leak | Toilet Most leaks are due to defective toilets. To check whether your toilet is leaking, place several drops of food colouring in the tank. If the water in the toilet bowl has become coloured 15 minutes later, that means there is a leak between the tank and bowl.