PUREFiltration, Inc. makes three sizes of pond filters.

They are for 300 gal. ponds, 1000 gal., and 3000 gal. ponds.

These filters have a recommended flow rate in order to work properly.

The 300 gal. filter has a 300 to 500 gal./hr. rate and the other two have 1200 gal./hr. Rate.