Calcium and strontium complex for balanced formation of the coral skeleton Ca | Sr | Ba Calcium, magnesium, strontium and carbonate are the basic foundation elements of coral skeletons. All of these elements need to be available in balanced proportions for positive coral health and growth. Red Sea’s CALCIUM+ contains blended salts of calcium and strontium in the ratio required by corals and is part of Red Sea’s complete Reef Care Program. Aquarium Type Average daily usage Liquid ml/100L (25gal) Powder g/100L (25gal) Mixed Reef 3ml 1.7g SPS Frag 6ml 3.4g SPS Dominant 4ml 2.2g Ultra Low nutrient SPS 2ml 1.1g Concentration: Liquid supplement: 1ml will raise the Ca level of 100 liters (25 gal) by 2ppm. Powder supplement: 1g will raise the Ca level of 100 liters (25 gal) by 3.6ppm. 1 kg will make 1.8L of stock solution. package size/volume : 500 ml (16.9 fl. Oz.)