Sump, refug?

[Klobianco12]

Know somewhat about them and how they work but do you need one for a tank or would it be good and established with out them and ok wit just a protein skimmer?

 

[crister13]

They're great for hiding equipment and stuff, you don't need one but they certainly help.

 

[Sniperhank]

Sumps are great in combo with a skimmer and a fuge for nutrient export.