Small Polyp Stony Corals are an important part of the reef structures in the wild composed of calcium carbonate.  The growth rate of the reef is different within the species itself.  While some grow fast others may only grow an inch every few years.  The need for clean water and consistency in calcium, magnesium and alkalinity levels.  This can be accomplished by either testing and adding supplements accordingly.  The alternative is to do water changes on a consistent basis with high-quality salt mix that has been tested for calcium, magnesium, and alkalinity in addition to the consideration of trace elements.