Actually there are 8. This is my return manifold and it feeds my display, refugium, and reactors... I drive my entire return system off one Hammerhead pump.
The 4 1" lines going down are for returns to the tank, the one coming off the top right goes to my refugium which oveflows into my display tank, the two ball valves facing down are used for reactors, and the ball valve off the left end is for future expansion. Behind is one of the 2" overflows from the display going to the sump.
I don't want to derail your thread with pictures of my own system as that will confuse your readers, but you can click on the Red House in my post to see all sorts of pictures of my system and how I built it. There are plenty of tank room pictures taken during construction and throughout the last year.