Fritz RPM Elements contain the essential building-blocks of reef keeping. Developed to easily adjust & maintain proper parameters, promoting healthier coral, coralline algae and invertebrates. It is impossible to maintain a healthy, vibrant reef aquarium without maintaining the proper levels of calcium, alkalinity and magnesium. FRITZ RPM Elements allows aquarists to maintain these critical components in their proper ionic balance. Unlike other similar products, Fritz RPM Elements do not contain unmeasured and unnecessary ions and metals, which unchecked can lead to toxicity in the aquarium. When used in conjunction with regular water changes using a high quality salt, like FRITZ RPM (Reef Pro Mix), RPM Elements will ensure the correct parameters for a healthy and beautiful reef aquarium!