A naturally occurring pond or lake contains its own ecosystem which has slowly developed over decades or even centuries. There are usually lots of plants lining the banks and floor, and sparse shoals of fish, eating only what nature provides. Natural ponds are also normally quite large, so any build up of waste is well diluted. A garden pond can rarely find its own balance. Garden ponds tend to be much smaller, containing fewer plants per litre of water, and many more fish, which are constantly been fed nutrients from outside the pond’s environment. Without the aid of a filter, a garden pond would soon build-up excess amounts of debris and toxins and would be uninhabitable for both fish and plants.

The flow of water around your pond should be considered when planning the pump’s location and the filter’s outlet sites. Any areas of the pond which are removed from the pond’s flow of filtered water may begin to stagnate as debris starts to build up.

Obviously it would be pointless if you set your pump up directly under the filters return as the system will only be filtering clean water. Ideally the pump and filter return should be set at opposite ends of the pond. It may be necessary, if possible, to install a satellite strainer to the pump if there are areas removed from the flow of filtered water, for example, if you have a figure-of-eight shaped pond.The pump should be slightly raised from the pond bottom so that vast amounts of debris do not hamper its running, any debris not taken in by the pump should be removed periodically as part of your routine maintenance.