If you are tempering an ingredient with a water meter, you need to let Fusion know how much water has been used periodically by entering a new reading with this window. We recommend entering reading on a consistent basis (for example, on the last day day of each month at the beginning of the day). We also recommend adding readings at least monthly, but not more than weekly. If you enter a reading too often, Fusion will not be able to calculate the amount of water being used very accurately. See the Water Meters and Tempering section of Core Concepts for more information.
If you click the Calculate Water Percentage button, Fusion will figure out the water percentage since the the last water meter reading based on the values you just entered and the amount of ingredient used during that time period. This can be used as a sanity check to make sure the reading is correct.
After you have made the changes, click the Save button. If you have changed your mind, click the Cancel button.
You can open this window by going to Fusion Core → Attributes → New Water Meter Reading or by creating or editing a reading from the Water Meter Reading List window.