Well, the tank is approaching 6 months now, actually. Much of the rockscape, fish, corals and inverts have been around for over a year. With 22 fish and probably close to 100+ various inverts that comprise the cleanup crew - it's fairly diverse. My skimmer pulls out the most wretched, foul-smelling skim imaginable. Dark green bordering on black. And I do need to empty it every 3-5 days.
I'm not suggesting you don't have to change your carbon more frequently, just with my setup I don't. I know this is specifically a "carbon" thread, but there's a lot more that I do with my tank every day/week/month besides just changing the carbon that is contributing to a healthy tank (and using premium carbon and other elements certainly doesn't hurt, either). Addendum: I tried attaching an image, but that R2R feature is apparently non-functional atm.