The BioMaster line of premium external filters is perfect for marine and freshwater aquariums. This filter boasts 4-stage filtration and is designed with sealed filtration pathways to ensure water travels the most efficient path through all filter media – creating optimal water quality and clarity. Water is first directed through the pre-filter’s activated carbon foams which remove toxins and odors, then into the main chamber with filter foams of differing pore densities and Hel-x Biomedia – all providing surface area ideal for the settlement of beneficial bacteria. To optimize your aquarium filtration OASE offers coarse 30, fine 45, and ultra-fine 60 ppi replacement foams to customize your pre-filter. The BioMaster filters are engineered with integrated safety locking features on the handle, pre-filter, and check valve in the inlet/outlet connection unit, ensuring no accidental spillage or messy maintenance. The EasyClean pre-filter can be removed and cleaned separately from the rest of the filter, which cuts down on maintenance and extends the life of your filter. Other filter features include simple priming for fast and easy startup, and adjustable flow control for the inlet and outlet. Easily integrate an OASE HeatUp adjustable heater into the BioMaster canister (HeatUp not included). BioMaster 250 is suitable for use in aquariums up to 70 gallons. Designed using German engineering and manufactured in Italy, this energy efficient filter is supported by an included 3 year warranty with a free 1 year warranty extension with online product registration. OASE BioMasterGrey Fish Filter in Gray | 55145