one of the guys on reef central refers to it quite a bit in his discussion of manifolds....
"use larger pipe too on the output of the CL
pump up to and around the manifold... and only reduce as needed at the tees for effluents. For example: ~ 5000 gph
water pump on a 120 gallon display with a 2"bulkhead feeding the pump and 1.5-2" pipe coming off the pump and running the loop for the manifold. Off the manifold 15 tees (three capped to give 12 running effluents for a 1 tee per ten gall ballpark/guide) come off the loop on reduction to say 3/4" (open nozzles) or 1" (flared nozzles)"