... 12x10, 12x12, 25x9, 25x10, 25x12mm. Bio filter media for pond, fish farming, aquarium, Koi filters and wastewater treatment.1. Product Description ... denitrification, dephosphorization, decarbonization, water purification.(4). Aquiculture (pond, fish farming and aquarium): denitrification, decarbonization, improve the living environment of ... %9999Life-spanyear≥10≥10PH5-115-11 Filter media for fish jar