Aqua Medic 400 Nitrate Reducer up to 100 gallons. The Mini Nitrate Reducer is an anaerobic biological reactor for the removal of nitrates from marine and freshwater 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.