The 5000 Dual Calcium Reactor SRO CR5000D is a high-performance calcium reactor designed to maintain optimal levels of calcium and alkalinity in saltwater reef aquariums. Its reverse flow design ensures efficient dissolution of aragonite media into the aquarium water, while its robust construction includes a PH probe holder for precise pH monitoring within the chamber. The reactor comes equipped with a powerful Water Blaster pump featuring silicone carbide shafts and bearings to prevent freezing issues and ensure reliable operation.