Pond Matrix is a high porosity biomedia that provides efficient biofiltration for the removal of nitrogenous waste in ponds. Plastic bio-materials provide only external surface area, whereas Pond Matrix provides internal macroporous surface area. These macropores are ideally sized for the support of nitrifying and denitrifying bacteria. This allows Pond Matrix, unlike other forms of biomedia, to remove nitrate along with ammonia and nitrite, simultaneously and in the same filter. Pond Matrix is completely inert and will not breakdown. It need not be replaced. It is also more suitable for use as a clean soil replacement for growing pond plants. Use 12 Liters of Pond Matrix for each 100 US gallons. Since the majority of the bacteria are internal, Pond Matrix may be rinsed when needed without damaging the filter. Pond Matrix is compatible with all types of wet or wet-dry filters.