The EB8 supplies power to the Apex via the Aquabus. So, if you don't have at least one, you will need a 12VDC adapter. There is also Fallback capability. In the event that communication is lost between the EB8 and Apex, each outlet can be programmed to change to failsafe state. I would recommend at least one EB8 and using the DC8 for extra outlets.
Todd