All the tanks are drilled in the center.They all lead to the 30 gal sump.Then 1 pump that pumps 1600 GPH returns to all the tanks.Each tank has it's own shut off valve.
i have the same type setup and will warn you about the corals, from overfeeding the fish to get them to spaun you will start to grow nuisance algea, just a heads up, also might wanna upgrade the pump for flow do not know if you are going to put power heads in each cube or not but might wanna take that into consideration