Reef Complete is a concentrated and comprehensive inorganic supplement designed to restore calcium strontium and magnesium in reef aquari to concentrations found in natural seawater. The ratios of strontium and magnesium relative to calcium are based on reef aquaria depletion rates relative to calcium. Although Reef Complete may be used alone it is designed for use with Reef Calcium which provides organic calcium. Non-acidic and non-caustic pH 8.3