The Aqua Medic 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 a mV probe (available separately).The redox potential or oxydation-reduction potential (ORP) is an electric value that is a parameter for oxydation and reduction process in the water. The redox potential is of special interest in the aquarium:To check the water quality in a seawater aquarium. The ideal range is between 300 and 400 mV. It can be raised to the desired value by injecting ozone into the protein skimmer. The higher the values are, the higher the percentage of oxydation is - thecleanerthe water is.To control anaerobi