New House with 27 Zones - Setup Help

I moved into a new house with a Hunter ICC2 system and 27 Zones (1 acre lot).

Here is the layout of the house:
-9 Drip Zones
-17 Rotors/Pop-Ups

I can either get 1 x Rachio 3 12-Zone and 1 x Rachio 3 16-zone and control program them independently (one in the morning, one at night), or possibly combine systems.

Would it make sense to combine all the drip Zones since they use very little water? Or do I really need 2 Rachios?

Also, is there anything special to know with Hunter wiring - like the wireless rain sensor?

TIA!

@mikerachio - first off, welcome to the community.

Even if all the drip zones were combined into one zone, there would still be over 16 total zones and the need for two Rachios.

There are two issues in combining zones - first will there be enough water pressure (volume) to serve both zones running at once. Second, are both zones identical in their watering needs (many times not, so one zone will be sub-optimally watered).

Coordinating schedules between two controllers can be challenging with the Flex Daily option as it can vary the run duration of a zone based on the calculated water needs.

So, is the plan to run Fixed schedules or Flex Daily schedules?

Regarding the wireless rain sensor - there is a support article showing how to wire it into the Rachio (it can only be connected to one controller). Some people don’t hook up an existing rain sensor to their Rachio and just let the Rachio controller check the weather. This can fail on the sudden, unforecasted pop up rain storm.

Thank you for the welcome and great info!

I think it makes sense to have 2 Rachio systems.

I was thinking about putting the drips on a fixed schedule (since all they’re doing is watering foundations and other small areas) on one system and the rotors on a flex daily (since they’re watering grass) on the 2nd Rachio.

I would have drips run at night and rotors run in the morning so they don’t overlap.

The original installer also has a map of the entire system listing the flow rates of each head and zone - so I can program that into Rachio.

Sound like a good plan? Any other recommendations?

@mikerachio - one doesn’t have to dedicate a Rachio to just drips or a fixed schedule as there can be multiple different schedules on one Rachio. Rachio support articles will state that there needs to be an isolator device to have a common shared by two systems. There are posts by others that say sharing a common wire doesn’t require an isolator device.

Is there a master valve or pump start relay in the system? If so, a simple relay can be used to share it between the two systems. I have posted this before. If you need this and can’t find the previous posts, reply back here and I’ll recreate it.