"Matrix? is a high porosity biomedia that provides efficient biofiltration for the
removal of nitrogenous waste. Matrix? is a porous inorganic solid about 10 mm
in diameter. Each liter of Matrix? provides as much surface (>~700 m2) as 170
liters of plastic balls! Plastic bio-materials provide only external surface area,
whereas Matrix? provides both external and internal macroporous surface area.
These macropores are ideally sized for the support of nitrifying and denitrifying
bacteria. This allows Matrix?, unlike other forms of biomedia, to remove nitrate
along with ammonia and nitrite, simultaneously and in the same filter."