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.Matrix is completely inert and will not breakdown. It need not be replaced,Use 500 mL of Matrix for each 200 L (50 gallons) of water. Matrix may be placed in any kind of filter.