Used DeNitrating Below-Sand Plenums (set of 4, each 12x16") suitable for a 90 gal aquarium, either freshwater or saltwater. The plenum system can greatly reduce the frequency of water changes by lowering Nitrate to negligible levels. The plenums are the heart of a passive denitrating filter system for any aquarium having a bottom surface of 18" x 48".
Complete with 4 anti-burrowing creature screens.
No sand is furnished. A sand sample (to show recommended grain size to provide a 3" deep sand layer over the plenum) will be provided along with a copy of set-up instructions.
A second system, not exactly as pictured, is available at extra cost.
