Mine is a custom made monster... 5 feet tall x 12"D with 4 needle wheel pumps. If I had to choose again, I would go with one larger Venturi pump because keeping all those needle wheels functioning is a PIA.
I still believe that size/height matter. It is about contact time.
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400 gal reef. Established April, 2007. 3 Sequence Dart, RM12-4 skimmer, 2 x OM4Ways, Yellow Tang, Maroon Clown (pair), Blonde Naso Tang, Vlamingi Tang, Foxface Rabbit, Unicorn Tang, 2 Pakistani Butterflies and a few coral gobies
My Tank:
http://www.canreef.com/vbulletin/showthread.php?t=28436