In the natural marine environment, essential trace elements exist in both anionic (negative) and cationic (positive) forms. With two complimentary solutions, PRO-CORAL K+ ELEMENTS and PRO-CORAL A- ELEMENTS supply the aquarium with all of the essential trace elements. The two solution approach guarantees optimum availability of the compounds and avoids unwanted reactions of the elements with each other. Tropic Marin® PRO-CORAL K+ ELEMENTS Trace Elements are natural minerals, which have essential functions in many of the biological processes of living organisms. Many cationic trace elements are associated with enzymes. These enzymes are not able to function properly without their associated trace element present. Several trace elements are involved in photosynthesis while other trace elements support building and stabilization of calcareous skeletons. A severe trace element deficiency can lead to bleaching of corals. There are no substitutions for trace elements, therefore, it is essential that all trace elements be added to the aquarium in a naturally balanced mixture. TROPIC MARIN PRO-CORAL K+ ELEMENTS is carefully formulated to support the healthy and continuous growth in the reef aquarium by replenishing all the essential cationic trace elements used by corals, invertebrates and algae. PRO-CORAL K+ ELEMENTS contains no phos-phates, chelates and other unnatural solvents. PRO-CORAL K+ ELEMENTS adds the following cationic trace elements to the aquarium: strontium, barium, chrome, manganese, iron, cobalt, nickel, copper, zinc, boron. Recommended dosage: Add 1 ml of PRO-CORAL K+ ELEMENTS per 100 l / 25 gallons US-gal of total aquarium system water volume per day in the circulation flow of the system. Trace element demand increases with increased aquarium population density. In heavily populated aquariums, dosage may be increased up to the maximum dosage below. Maximum dosage: Do not exceed a dosage of 2 ml per 100 l / 25 US-gallons of aquarium system water volume per day. The regular dosing of PRO-CORAL ELEMENTS can be automated with a hose pump (dosing pump).