The BioMaster line of premium external filters are perfect for marine and freshwater aquariums. The BioMaster 250 boasts 4-stage filtration in a compact design. Biological, mechanical, chemical, and prefiltration all work together to provide your aquarium with optimal water quality and clarity. The BioMaster filters are designed with sealed filtration pathways to ensure water flow is getting the full benefits of prefiltration, filter media for clearer water, Hel-X Biomedia provide a large suspended settlement surface for microorganisms, and activated carbon for ideal nutrient reduction and removal of toxins. The EasyClean prefilter module can be removed and cleaned separately from the rest of the filter for high efficiency and to extend the life of your filter. The water flow can easily be adjusted on both the inlet and outlet adapters for the filter. Created for convenient placement under the aquarium. Created for convenient placement under the aquarium. Install the included diffuser and spray bar for uniform surface movement and additional dissolved oxygen for ideal water quality. This filter also features a carrying handle for simple moving and maintenance. This energy-efficient design includes a self-priming function for easy operation on startup and after cleaning. Includes a shut-off automation with built-in check valve to prevent leakage when cleaning the filter. Designed using German engineering and manufactured in Italy, this quiet operating filter is supported by an included 3 year warranty with a free 1 year warranty extension with online product registration. Customize your prefilter by combining coarse, fine, ultra fine, and activated carbon filter foams.