Pond Logic BioBalls filter media provides an excellent source of secondary filtration media to harbor beneficial bacteria and keep your pond healthy, balanced and clear, Pond Logic BioBalls are a lighter and more effective solution to biological filtration than traditional porous stone, Pond Logic BioBalls conform to the shape of your filter box, are easy to clean and last forever, Each box of Pond Logic Bio Balls contains approximately 200 BioBalls and filters around 1,000 gallons of pond water with a minimal fish load, Help keep water healthy and clear without chemicals, Easy to clean, re-usable and last forever, Designed to provide maximum surface area to accommodate beneficial bacteria, Dimensions: 1, 5"" Diameter, Weight: 0, 3 Ounces Each (200 weigh roughly 3, 5 Pounds), 200 BioBalls filter approximately 1,000 gallons, SKU: AES303