We are releasing to the Webapp the ability to empty or fill individual zone soil moisture levels on Monday.
So, if you want to reset your zone levels back to zero so flex schedules will run the next day, or you want to simulate filling the tank with water (your zones are topped off) you will be able to do this from the soil moisture graph.
iOS and Android will support this functionality when they have soil moisture graph functionality.
iOS is submitted, waiting for approval, Android should be done early next week
Onward, and upward!