Aqua-Pure External Biological Filters
The Aqua-Pure line of filter systems is by far the lowest of maintenance combined with the best of clear water quality.  No more pre-filter mats to clean!  No more having to climb into the pond to pull out the filter.  The settlement chambers offer easy-to-open valves to rinse out sludge accumulation.  This filter's unique design channels the water to thoroughly flow up-and-down through all chambers of filtration material.  The vortex pre-filter spins solids out of the water (and is available in the Aqua-Pure 6000V model only).  The initial chamber of brushes removes larger debris, continuing on through bio balls, open weave filter mats, then on to a tight weave of sponge material for final fine filtration before returning to your pond.  Made of durable construction of dark green color, aesthetic wooden slats for the top are also available to camouflage.  Best to use with a submersible pump in the pond protected by a pump basket.  This filter is an excellent choice for Koi ponds.