Calculate the application rate of each similar zone by using the following formula:

- 231 is going to be the conversion number or constant.
- The GPH depends on the size of the built-in emitter, Hunter manufactures .4, .6 or .9 GPH (1.35, 2.35, 3.75 l/hr) emitters in HDL.
- Spacing is the emitter spacing, Hunter manufactures 12, 18, and 24 inches (30, 45, 60cm) emitter spacing.
- Distance is the sideways measurement between the lines of drip installed.