Maximum Number of Zones

[HereComesTheRain]

There is no maximum.

Go to OPTIONS > Station handling > Station extensions and increase the number.
Each increase of 1 adds 8 stations.

Hi Dan

Thanks for such a fast reply.

Is there a "simple" guide for building a 16+ zone system?  I plan on using a Pi 3B+

Would the following be the correct board for 16 zones:

https://www.dx.com/p/7034-16-channel-12v...s_PJi2ZOL4

Could I use two of those if I wanted 30 zones.  

Would I be better off if I went the DIY route: https://github.com/Dan-in-CA/SIP/wiki/Relay-interface

The Pi 3B+ is very picky about power and was wondering what power supply you would recommend for the relay boards?

I have been overcome with madness and attempting to upgrade my raised bed garden so that each bed has its on control valve.  I have gotten tired of manually rerouting supply pipes from a five zone manifold system which has been in place for a number of years.

Thanks again for your fast reply.