Pressurized filters

From Koipedia

Another kind of pond filter is the Pressurized filter, which is a sealed unit placed after the pump. They have the advantage of placement flexibility, they can be located below pond level, above pond level or pretty much anywhere. One type of pressurized filter is the bead filter which some have the nice feature of a "back flush" which allows you to clean the filter buy turning a knob.

See also: Above pond filters See also: Gravity fed filters