I recommend Seachem stuff because they have always worked for me, Seachem supports our club here in Atlanta, and the sales rep. has come to meetings and explained their products to me. The other brands all claim to do the same things and many people swear by API products. But I only recommend what I know works. For details I look at their website,
http://www.seachem.com/home/home.html. But if you still have questions, you can talk to them.