Filtering medium for biological and mechanical filtration for fresh and marine water aquarium. Zeolite material comes from vulcans and its molecular structure is very regular. Its absolutely high porosity adsorbs ions and molecules of different composition and size, so that it neutralizes ammonium, silicates, nitrites and nitrates. ZEOLITE from PRODAC INTERNATIONAL has an inside surface of 600 sq m²/g, this guarantees the total absorption of polluting organic and inorganic substances.