Gravity Filters are large, hold a lot of waste and are the easiest type of filter to clean. They are perfect for heavy fish stocks or messy fish such as Koi. Some models have an in-built UVC to reduce green algae. Must be mounted with the outlet above the pond water level.
Need help choosing a suitable filter for your pond? Click on one in your price range - you will go through to a page with a lot more info which will help with your choice.