Red Sea KH Coralline Gro - A trace element and buffer complex that promotes the development of Coralline Algae. Coralline algae will grow naturally, without any special supplements in all reef systems optimized for hard corals. KH Coralline Gro is a complex of carbonate buffers, potassium and trace elements such as iron, formulated in the ratio taken up regularly by the coralline algae. To promote coralline algae in fish only or soft coral aquariums the alkalinity needs to be maintained at approximately 3 meq/L (8.4 °dKH) and specific minor and trace elements need to be readily available.