The return mainfold is plumbed into a Dolphin DP 900 it's not a closed loop. That pump sits in a the 20gal(sump) its 24"x12"x (i think)16" the refugium is a 15gal high 20"x10"x(i think)18". Fitting the tanks in was quite a challenge, I went thru many itterations to find the right sizes and actually broke a 15gal high in the process :? . But it turned out to be signifigantly cheaper than a custom acrylic unit that would fit to achieve the same thing.
Sounds good. Thanks for the link you PM for the local guy. I'm going to check them out this weekend. I'm having trouble with space especially since I have two external pumps.