Hi Ethan, 

Netro uses the area and depth flow rate(inch/hour) to calculate the water usage and the equation we use is 

Area(inch^2) x depth flow rate (inch/hour) x time (hour) = water usage(inch^3) 

To have 50 gallons every other day for your zone, you will first need to calculate the watering duration according to the equation and then adjust smart watering or create your own programs. 

 You can choose boost mode to increase the watering amount. You can also choose "customized" mode to adjust watering by providing the preferred moisture level and flow rate of your sprinklers. (you will see the estimated water time after adjusting the percentage) 

Thanks, 

Wency 

Netro Support