Rishma,
Well, at the risk of going off-topic, where exactly is the evidence that iodine is "widely accepted to be unnecessary, and possibly detrimental"? This is news to me. While it may be true that iodine is not actively taken up or assimilated into coral tissue, it does not necessarily follow that additions are unnecessary or detrimental. It's effects in detoxifying excess oxygen from photosynthesis, and thus reducing bleaching, seem to be pretty well-founded (Delbeek and Sprung, and others), as are it's disinfectant properties. And every single reference book I have (D&S, Fenner, Borneman) lists iodine as important for good expansion and long term health of corallimorphs and other soft corals. I readily agree it is very easy to overdose, but so are many things we add to our systems. In the absense of solid scientific evidence to the contrary, I don't see why occasional careful dosing of iodine is a bad thing.
Comments?
paul