Red Sea Supplement pack for healthy Coral growth contains 3 x 250ml bottles each of Reef Foundation A B & C.Reef Foundation ACalcium and strontium complex for balanced formation of the coral skeleton. 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 Seas Reef Foundation A contains blended salts of calcium and strontium in the ratio required by corals and is part of Red Seas complete Reef Care Program.Reef Foundation BCarbonate & buffer complex for balanced formation of Coral Skeleton. 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 coral health and growth.Red Seas Reef Foundation B is a complex of carbonate and other buffers present in seawater that maintain proper alkalinity and pH and is part of Red Seas complete Reef Care program.Reef Foundation CA magnesium complex for balanced formation of coral skeletons.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 Seas Reef Foundation C contains blended salts of magnesium and is part of Red Seas complete Reef Care Program.