Dear customer,
We recommend watering only when the soil is dry enough in order to draw more oxygen into the roots, leading to a lusher landscape. For grass, we suggest you can set moisture to skip watering as "90%"; moisture to add watering as "60%". This is also the default setting for grass in Netro watering mode. Setting moisture to add watering as "20%" would be a bit low.
Thanks,
Netro Support