coleus - have a look at the new reef dynamic biopellet reactors. dedicated tumbling pump which has enough suction to pull in water from your sump as well. its hard to explain but you will understand after you see the videos on their product page. there is some very good info on bio pellets and there use that you might like to see.
http://www.reefdynamics.com/Reef-Dyn...s-p/bpr135.htm