I just moved into a new house. The front yard is finished and I am in the process of finishing the back yard. The front yard has a Hunter Pro-c controller (outdoor) and has 4 stations attached. I will need around 4 to 6 stations for the backyard. Can I use this same controller for the backyard? I saw on-line a controller expansion module for the Pro-C that adds 3 stations.... is that what I need?