150gal ZEO que dramatic music

[The Grizz]

Hey John tank looks awesome but I expected nothing less. This is going to be a stupid question from a beginer SW but........ what is the purpose of the carbon? I have asked several different people what all should be in the sump and the only answer i really have received is some sponge to catch larger debri. You put it in your filter sock I am guessing. I know it is highly nessesary in FW have used it for years.