Red Sea Coral colors Fe and trace supplement-C is part of the complete range of complementary major, minor and trace element complexes which together provide the needs of corals. Coral colors C supplement contains iron, manganese and other trace elements that are associated with many biological processes, one of them being the production of the green/yellow pigments in the soft tissue of corals. To ensure coral health, the ppm level of these elements must be maintained within a narrow band and therefore should only be dosed according to a measured requirement of the aquarium. For optimal results, dose according to a measured uptake of iron using iron pro test kit. Iron and complementary trace element complex that promote the green colors in corals. Available in 500-ml bottle.