BRS Two Part Calcium and Alkalinity Solution

[ALang]

I really don't know. It depends on the levels of Cal, Alk, and Mag in your tank right now, and how much you need to raise it, and how often (as in how much/how quickly do your corals use up). Also some people will add some to their salt water prior to a water change if they have tested their brand of salt and find the levels lacking.
I've always used AragaMight when I used to keep just softies, and I never tested my levels until I started to keep some of the LPS and couldn't keep them alive for long. I was also using an old set of test kit as well, and gave myself false readings. So for the longest time, I never dose anything seriously. I am interested in trying some sps frags that I bought, so hense my order. I have a 133g mixed LPS ans SPS and a 90g mostly soft corals. So it is entirely up to you. I may need all of my 1 gal powder for all I know. Can't really say.