Aquarium Pond Filter Sponge Foam Replacement Media 15-50 Ppi Adjustable. Upgrade Your Aquarium with This Top-notch Biochemical Filter, Designed for Both Freshwater and Marine Environments. This Durable Filter Efficiently Breaks Down Waste While Promoting the Growth of Essential Nitrifying Bacteria, Ensuring Superior Biological Filtration. Its Versatile Design Makes It Easy to Integrate into Any Aquarium Setup, Offering Durability, Excellent Water Flow, and Simple Maintenance. Key Features: - Enhances Growth of Nitrifying Bacteria for Optimal Filtration - Effectively Decomposes Waste - Durable and Robust Construction - Suitable for All Aquarium Types - Easily Adaptable to Various Setups - Lightweight with High Water Permeability - Reusable with Proper Maintenance - Color: Black Usage Instructions: Allow the Vacuum-packed Filter to Expand over 1-2 Days for Optimal Reshaping. Replace the Bio-sponge Every Three Months for Continuous Bacterial Support. Package Includes: - 1x Biochemical Filter Cotton (Note: Manual Cutting May Result in a Size Variation of 0-2 Cm.).