From the decoder outputs to the individual solenoids, use standard irrigation wire sized for the length of the run.
Wiring from the decoder to the solenoid should not exceed 150 ft/45 m. If decoder-to-solenoid distance is over 20 ft/7 m, use "webbed" or twisted wire to aid in surge suppression. This is especially important in high-lightning areas.
The decoder is often in the same valve box as its solenoids. In these cases, standard 18 AWG/1 mm wire is acceptable.
Each decoder output has the capacity to operate two standard Hunter solenoids. When doubling solenoids on a decoder output, wire the solenoids in parallel rather than in series. The decoder station output leads should run to the two leads from the first solenoid, then connect (usually in a three-way splice) to the leads from the second solenoid.