Sump?

[deton8it]

First of all hello everyone. I have had a saltwater tank for about 5 years now so I'm not exactly new to this. With that said, besides aesthetics is there a difference between running a sump or running a HOB bio wheel type filter and a HOB skimmer? I have never run a sump but my LFS says that I really should. I cant figure out how it would be better than what I currently have.
Thank you
John

 

[kacey]

A sump increases your overall water volume which increases stability of the system. It provides a place to do water changes and top-offs that won't stir up the sandbed or stress the fish (you can do them from the sump where the fish pretty much won't even notice). It also provides a space for a refugium which is great for nitrate reduction and a haven for microcrustaceans to breed without being immediately eaten by the critters in the tank. You can also stick your equipment down there so your tank looks tidier. Overall, it's just a handy thing to have.