Running Carbon - How much is too much?

[TAZ]

Hi all,

I was just wondering how often (if at all) do people run carbon in their systems. There are some people who say they run it for a couple days, every couple weeks. There are others that run carbon all the time in their system. Right now I run Carbon all the time, and about once a month I replace it with new stuff. By doing this am I harming my system in the long run? Should I be adding anything to my system to help supplement anything the carbon might pull out?