Sunterra 330106 Post -Filter Replacement Pond Filters for use in Sunterra 300106 and 300107, Blue and Black Replacement Filter for Bio -Filter Pond Filters that clean up to 2,000 to 3,000 Gallons Regular Maintenance of Existing Filters Ensures the Pond Filtration System Operates at Optimum Performance Replacement Pack Contains One Coarse Filter and One Fine Filter