I've had my tank up and running for almost a year now,and have not had to add anything.I do use frozen foods and water changes with Instant Ocean also.I check my levels every now and again and nothing needs attention...knock on wood!As I have seen from being in this bb,everyone has a different situation.And,once again I think it is trial and error with each individual setup.I only have a combined 120w of normal output floresent lights on my 55 and my 17 different species of corals are thriving.I don't know why,and I am sure more light would help them out,but I'm leaving well enough alone for now.