I'm sure this has been posted before, I tried to search.....
What else does a skimmer remove besides fish poo, like essential elements. strot/moly, iron, iodine? And if it does is it a drastic removal?
I know it removes salt. I also remember a discussion about the contents of skimmate, but I can't remember what the context was. Salt study maybe? or Auto-toppoff.
The two writers I read most from when starting up had very differing opinions (Fenner and Borneman) about skimmers and carbon (somewhat) so I just run both now, feeling that it does more good than bad, personally. HTH