So I was poking around in a MarineDepot catalog and saw Red Sea Reef Colors Pro Kit - Reef Care - Iodine, Potassium & Iron, and it really got me thinking. What would i test these for? I really don't have an answer for this other than for "Reef Colors". So I was wondering if anyone tests for these things? Should I be testing for these things? I assume this is not something I should test for even on a weekly basis or if at all. I don't know enough about these three elements in my tank to even know what level they should be. So what i am really wanting to know is, who tests for these things and what have you learned about your water chemistry, or your corals health, in regards to these tests. If you have an article you have read which has information on this topic, I would love to have a link posted here because I really enjoy doing the reading and learning more about this hobby, but i would really like first hand experience if you have that as well.