Small Polyp Stony corals, also known as SPS corals, are a favorite among experienced coral reef hobbyists. Our SPS corals for sale build a calcium carbonate internal skeleton that makes up the bulk of the reef structure. Due to this SPS coral frags require a consistent level of calcium and alkalinity. SPS corals usually require strong light and water flow to thrive. Buy Small Polyp Stony (SPS) coral online from our collection below.