[Subsea]

Jaubert Plenum uses a false bottom below sandbed. Until Julian Sprung and Charles Deelbric published Reef Aquarium Volume III, there was little substantiated literature that the plenum accomplished anything. The biggest reason that laboratory test could produce no differrenceis was because of the short duration of test.
This method uses bacteria to perform nitrification then in the depths of the sandbed denitrification chemistry. The use of large substrate, Caribsea Florida Crushed Coral, at 2mm-5mm provides a greater depth for reduced oxygen conditions. This means more faculative bacteria and more denitrification. The single most important thing about this method is to keep detritus from penetrating into sandbed. Janitors at the surface should include micro stars and the two pod brothers, amphipods and copepods. Everyday, I would stir the top 1" of sandbed with numerous feathers coming out to eat: feather dusters and sea apples. To complete the maintenance on this method the sand should be vacuumed once a week.