The aim of fitting a pond filter is to establish and maintain adequately healthy water conditions for the long-term well-being for the pond inhabitants. Like pumps, filters cam be installed either in the pond or outside. Filters also employ a variety of different filter media. one key point to bear in mind is that, for a filter to work efficiently, it must be teamed with a pump that supplies it with a sufficiently strong flow of water. Manufacturers recommend that the entire volume of the pond should be passed through the filter approximately every two or three hours. Internal filters, which are fitted underwater, are generally quite straightforward to install and dismantle. Most models come in a self-contained units, complete with a single filter medium or a selection for media and inbuilt inlet and outlet ducts. External filters can either be built into the pond design or bought as complete units. Off-the-shelf models usually incorporate all the necessary pipework and filter media - and often a UV clarifier as well - within a single cistern-type container. The fittings on such units are easy to connect to the servicing pond pump and the pond itself. building a sophisticated filter into the fabric of the pond is far more complex, and is usually reserved for specialized Koi pools.
