Filter brushes are Japanese in origin and are suited for both mechanical and biological filtration.
As pond water passes through a series of brushes, the bristles filter out suspended solid, while providing ample surface area where the nitrifying bacteria can colonize and thrive.
Cleaning of the filter brushes is a simple task of removing them from the filter and shaking them out. Remember not to use tap water to rinse them, as this will only serve to reduce or eliminate the beneficial bacteria which is growing on the brush.
This filter brush has a diameter of a 4" and is available in 13" or 23" lengths.