As I've explained in PM's, I don't buy into the big "You need this additive" farce. Most of them are IMO designed more to separate you from your hard earned fish money, than to accomplish any real benefit to your tank. It's been my experience that you can toss all of the money sucking supplements in the trash, got all the necessary trace elements your tank will ever need by regular and frequent water changes, and a nice side benefit is that your tank and fishes will be happier and healthier than they would be if you used every single supplement that they tell you that you "GOTTA HAVE THIS!" Many of them are IMO, pure snake oil, and the rest, well, they are just not necessary.
By the way, did I memtion that I believe in doing water changes? If there's something wrong with your tank, do a water change, If you have a sick fish, do a water change, Got a few $$$ you don't know how to best spend on your tank, do a water change...