I would just leave the threshold as a default. And as far as schedule am assuming you have cool season grass what type of spray heads do you have. You also need to know what type of soil you have that way you know what is your AWC. For flexible daily start with one zone first you get that zone dialed in for a few weeks and then apply it to the rest and leave the other five zones on fixed schedule Rachio would choose the time for the fixed schedule. Here you can check your soil type. Using Web Soil Survey to define your soil settings
