The Mantis Calcium Reactor CR200 is designed to maintain optimum and stable pH levels for corals, whilst balancing calcium, alkalinity, magnesium and trace elements. CR200 is ideal for larger aquariums up to 1200ltrs. Features: Controllable DC Tornado 4000 pump - Reverse flow and CO2 recirculation design - Auto Fill bubble counter - Effluent control valve - Easy maintenance - Internal or external installation.