Koi Pond Fish Tank Filter Media For Clear Water. Transform Your Aquarium or Koi Pond with Our Cutting-edge Biochemical Filter Media, Crafted to Enhance Biological Filtration and Foster the Growth of Beneficial Bacteria. This Advanced Solution Ensures Your Aquatic Environment Remains Clean and Vibrant. The Distinctive Geometric Design Optimizes Surface Area and Filtration Efficiency, Supporting a Healthy Ecosystem. Versatile and Adaptable, This Filter Media is Available in Several Sizes to Seamlessly Integrate with a Wide Range of Filtration Systems, Making It the Ideal Choice for Any Setup. Sizes Available: - 10x10mm with 4-5 Holes - 15x10mm with 6 Holes - 25x10mm with 19 Holes - 25x10mm with 37 Holes - 25x5mm with 64 Holes Experience Easy Maintenance and Increased Energy Efficiency with a Lightweight, Stent-free Design, Ensuring a Balanced Aquatic Environment with Ease. Features: - Optimized Surface Area for Superior Bacteria Growth - Stent-free Design for Enhanced Flow and Efficiency - Low Maintenance - Multiple Sizes to Fit Various Filter Systems - Lightweight and Effective Design *Note: Size May Vary by 3-5mm Due to Manual Measurement.*.