Bio filter media for Pond, Fish Farming, Aquarium and Water treatment Size: 10x7, 10x10, 12x10, 12x12, 25x9, 25x10, 25x12mm. Bio ... treatment of wastewater reuse.(3).River regulation: denitrification, dephosphorization, decarbonization, water purification.(4). Aquiculture (pond, fish farming and aquarium): denitrification, decarbonization, improve ...