I've been using seachem Reef Builder as my buffer and seachem Reef Advantage for calcium... I'm looking at the BRS options for dosing alk and calcium, which are significantly cheaper than Seachem but I am unsure if they will be as effective. I know that Seachem Reef Advantage says it also includes Magnesium and Strontium and typical depletion ratios. BRS doesn't do that.