Pressure filters are sealed, external units that use a pond pump to push water through mechanical (sponges/foams) and biological (bio-media) filtration stages, often with an integrated UV Clarifier allowing it to deliver pressurized, clear water for waterfalls or streams. Most feature a backwash system for easy cleaning. Because it's sealed and pressurized, it can be placed anywhere, even buried, and still push water uphill for features.
