Can anyone advise me on the usefulness of Kent Freshwater Essential? I am curious if it replaces or is similar to a Seachem product in purpose. I have read its description, and it is recommended by some online fish dealers as necessary with some fish. I have a planted tank and am already on a schedule with additives such as Excel, Florish, Iron and Phosphorus - all by Seachem and I am curious if the Kent product is really necessary. Thanks.