Bio filter media for Pond, Fish Farming, Aquarium and Water treatment Size: 10x7, 10x10, 12x10, 12x12, 25x9, 25x10, 25x12mm. Bio filter media for pond, fish farming, aquarium, Koi filters and wastewater treatment.1. Product Description of Bio filter media:Bio filter media is a new suspension bioactive carrier, it according to the different nature of sewage in polymer materials (HDPE and CPE) to ...