Red sea reef foundation a is a calcium and strontium complexrobust coral skeletons are essential for all reefs and only acheivable by ensuring the basic elements calcium magnesium strontium and carbonate are readily available and in the correct ratio to each otherif they are not in the correct ration the coral skeleton can form as a fragile calcitecan also be used as part of the stage 1 reef foundation in the red sea reef care program the reef foundation stage provides a complete solutio