... Pond, Fish Farming, Aquarium and Water treatment Size: 10x7, 10x10, 12x10, 12x12, 25x9, 25x10, 25x12mm. Bio filter media for pond, fish farming, aquarium, Koi ... Bio filter media:(1). MBBR (Moving Bed Biofilm Reactor) wastewater treatment.(2). Biological treatment of wastewater reuse.(3).River regulation: denitrification, dephosphorization, decarbonization, water purification ...