Honestly I don't know. My Ca/Alk is good and I dose with Seachem. It has Mag and Strontium in proper proportions, but I don't test Mg. As far as my Ca/Alk it is not hard to maintain. I don't have to dose that much. I do frequent WCs, so I can't imagine being very deficient in anything. Especially macros. My other stuff is all happy. The Galaxy is doing good, and my Shrooms are reproducing. Polyps growing like crazy.