Ok so my tank is running great thanks for all previous help on here to start me up. At this point I have a %100 survival on many corals and only 1 unexplained fish tragedy of out of 15 live and happy fish. My questions are about all these supplemental additives and chemicals I see on the shelves. I randomly add zooplankton and essentials both from Kent. But maybe because I read the label, like a woman with her wrinkle creams and miracle antiaging supplements, lol. Back to reality, iodine, calcium and what ever have you, are these good to ad or are they just a sales gimic.