Good sump design.Your skimmer should really rock with it being configured that way in your sump.Graphixx is right on about mandarins,mine never accepted any foods,they have a specific diet which requires the need for lots of pods in your tank.The best advise i can give to get a nice pod population is to feed your inverts alot.Start off small,maybe 2-3 times a week at night with the lights off.Eventually,step it up until your doing daily nightitme feedings.Use fine particulate foods like Golden Pearls(smallest size-50micron),LIVE phytoplankton like DT's,and mysis shrimp for corals.