FBF is short for 'Fluidised Bed Filter'. These are basically a large tube or triangle shaped container containing sand in which water is forced through causing the sand to be agitated.
This type of filter is very efficient for its size as a nitrifying biological filter as the constantly moving sand provides a much greater surface area for bacteria to grow on and the turbulent water provides good oxygen supply to the bacteria.
- Typically one pound of sand is approximately able to handle 100 US gallons of an average stocked aquarium.
- Normally found in large aquariums or Fish shops.