ZenBlue CBF-350 Mechanical and Biological Filter for Ponds, 1585-Gallon Maximum Flow Rate of 1585GPH Requires Pump with Minimum Output of 1190GPH Suitable for Ponds with Heavy Stock Koi up to 790 Gallons Suitable for Ponds with Small Mix of Fish and Koi up to 1188 Gallons 1 Year Warranty