Like the smaller Calciumreactor, the Calciumreactor 5.000 is a closed system, designed for universal use. It is supplied with an internal circulation and a connection port for a pH probe with standard thread. The reactor has a volume of 30 l and comes with a bag of Hydro-carbonate (50 kg, 110 lbs). The flow rate through the reactor shall be adjusted depending on the Calcium demand of the aquarium, to 12 - 30 Liter /hr (3 - 8 gph).