Reef Advantage is equivalent to dry Reef Complete. It is a buffered (ph 8.3-8.6) optimized blend of ionic calcium magnesium strontium sodium potassium and other salts designed for reef aquaria supplementation. Unlike limewater (Kalkwasser) Reef Advantage foes not have a caustic pH and will not deplete magnesium. Used as directed it will not deplete alkalinity. For each 100 mg/L calcium Reef Advantage also delivers 10 mg/L magnesium and 0.5 mg/L strontium proportionate to natural depletion rates (when used with Reef Builder)