Yes, you can add a second Sprite or Spark controller as you told.
Key Tip: Ensure the watering schedules of both controllers do not overlap. Running both simultaneously could cause electrical back-feed issues to your pump relay. Alternatively, if a faucet is available, our Pixie timers can expand your system wirelessly.
For a safe wiring diagram specific to your bore system, please email us at support@netrohome.com.
Best regards,
Candice Wang
Netro Inc.