Weird, I've never heard of someone running too much carbon before. I would imagine someone running zeovit or similar would have really clean water like yours. Maybe it's something your missing? The only thing that I can really think of, is maybe they were used to the amount of DOC's you had before, and when you put the media in it striped them out of the water fairly quick and they are not getting the full nutrients..? I dunno, just thinking out loud I guess.. I hope you fidn the answer soon, SPS's are my favorite.. What types do you keep and which if all are being effected?