Salifert Calcium Test KitCalcium is a major constituent of calcareous algae, skeletal material of hard corals and the skeletal needles of soft leather corals. Calcium also fulfills many biological functions. Low calcium concentration retards coral and calcareous algae growth. Natural saltwater contains 400 450 mg L calcium. In a stable aquarium environment the calcium content should not fluctuate by more than 15 mg L. Calcium test kits should be able to monitor comparable