Goplus Pressure Bio Filter 10000L w/ 13W UV Sterilizer Light for Pond Koi Water 4000GAL UV Bulbs System- It is equipped with UV bulbs which works to reduce the presence of single-celled algae by reducing its ability to reproduce. It is suitable for improving the water quality to provide a clear and healthy pond for your fish. Strong Filter Capacity- This filter is suitable for ponds with normal fish load 2500 gal and ponds with heavy fish load 1500 gal. With such powerful capacity, it is an efficient filter to purify ponds. High Strength Outer Casing- This filter is made of high quality material and the outer covering is high strength, which is durable and waterproof. You can place it on the shore or underground. It can be used for a long time. Multiple Function Tool- It can not only draw water, but it also can be used to filter the pond with bacteriostasis function, which be a good choice for you to clean your pond with one machine. Easy to Operate and Clean- The filter comes with clear instruction, it can be easily for you to use. And with the automatic cleaning function, which can save much your time. Really convenient for daily use.