I don't use carbon, but I voted yes. I does a pretty good job of removing particles as well as removing odor. The problem is that is expensive since you need to replace it at least once a month. If you're only dealing with one smallish tank, then that's not such a big deal, but if you have multiple large tanks you'd be spending a lot of money. Besides, if you have your filtration setup for water polishing, you should not need the carbon. I've sometimes used a dedicated filter on each tank just for water polishing - blue bonded filter pad and poly-fil (from Wal-Mart). The only time I ever use it is to remove medications.