Reef Builder is an alkalinity booster but will hae no immediate impact on pH although there will be a gradual drift to pH 8.3 or tendency to stabilize at that pH. Used as directed Reef Builder will not depelete calcium magnesium or strontium that usually tend to precipitate with increasing alkalinity. Reef Builder is compatible with Marine Buffer and is similar to it except that Reef Builder will not directly raise pH. Reef Builder is compatible with all Seachem Reef Products