I'm sure this topic must have a thread but I've been unable to find one. When I had a reef 30 years ago carbon in the displays filtration was used constantly and in large amounts. Getting back in the hobby now I hear little discussion of it. My current system is < 1 yo and I have not used any as yet but have a reactor set up for any use necessary. Routine use, occasional intermittent use, only to remove specific toxins, meds etc that you know or suspect are present? What's a new reefer to do?