Aqua Medic 1000 Nitrate Reducer up to 250 gallons. The Maxi Nitrate Reducer is an anaerobic biological reactor for the removal of nitrates from marine and fresh water aquaria. It has a large volume of 10 liters (2.5 gallons) and an internal circulation pump. The Nitrate Reducer works with a flow rate of 1 to 4 liters per hour (0.25 to 1 gallon per hour). This condition, in the absence of oxygen, promotes special bacteria to metabolize nitrate. Denimar tablets or Deniballs are used as an organic energy source. To monitor this process, it is possible to use a redox potential monitor (ORP monitor) in conjunction with the probe inserted in the supplied port. The Nitrate Reductor is a closed unit that can be integrated in filter systems, but it may also be used to stand alone