JBL TraceMarin 3 contains a further 16 trace elements such as manganese, zinc, iron, nickel. Molydenium, vanadium, rubidium etc, to meet the special needs of all hard corals, soft corals, bivalves and other invertebrates as well as calcareous algae in the reef aquariums. Deficiencies of these in the aquarium can cause stunted growth in many invertebrates. JBL TraceMarin Contains no colouring or additives and no complex-forming ingredients, as these have proved to be problematical in the care of reef aquariums. Optimum effectiveness when used in combination with JBL TraceMarin 1 and 2.