Closed system denitrification unit for use outside of sump or aquarium. Suitable for freshwater or saltwater aquaria up to 400l. Supplied with Deniballs & Denimar and reducing T-piece 12/16 ? 4/6mm for creation of bypass. Please note: If redox measurement is required, the pressure resistant electrode (220.19) must be used. Total height 38cm. For further information on automation of this item, please contact the ab Aqua Medic Technical Department.