Essential trace elements formulated to replenish concentrations needed in an active reef aquarium, essential cationic trace element supplement for marine aquariums.Tropic Marin Pro-Coral K+ Elements contains cations of the trace elements:Boron, Chrome, Cobalt, Iron(Fe), Copper, Manganese, Nickel, Strontium and Zinc These essential minerals are carefully formulated utilising proportions designed to replace depletion from the consumption by corals and invertebrates.The addition of Pro-Coral K+ Elements supports ideal growth and natural colouration of corals and invertebrates.Together with Pro-Coral A- Elements, Tropic Marin Pro-Coral K+ Elements supplies a complete profile of the essential trace elements in a particularly stable, biologically available form with only two solutions.