The mV Controller is designed for monitoring and controlling the redox potential (or ORP – oxidation-reduction potential) in aquaria. The unit has a broad controlling range from -500 to a +500 mV, and a measuring range from -1000 to +1000 mV. It can be used to control the supply of ozone in saltwater aquaria and/or for the control of nitrate removal in anaerobic biological filters (Nitratereductor). The unit is supplied with a BNC connection for an mV probe. The use of an original Aqua Medic electrode #220.16 is recommended.