To Sump Or Not To Sump

[Palster]

Thanks to everyone for responding. Being relatively new to saltwater fish keeping I never considered the nitrates issue with running these filters on a tank with messy eating fish. I will definately go with a sump. I currently am running a sump on my 90 gallon tank (I am going to basically copy the design). The only questions I have in regards to the sump are is it beneficial to run Bio Balls and or sponge filter media in the sump? The sump that I currently have does have both.