The Pond Pump Guide

Their are many different types of pond pump, but the type and size of the pump that you will need really depends on the size of your pond, the type of filter you choose and what water features you wish to run in addition. Garden pond pumps come in all shapes and sizes and there will be several to choose from that meet your requirements. I have always used the Blagdon Amphibious range, one P9000 ran continuously for ten years before it needed a new impellor! Take some time, think about what your dream water feature would be.

Will you have a waterfall? If so how wide do you want it, how fast the water flow? A gentle soothing trickle, or a roaring niagra to drown out the neighbours?

Garden fountains are very popular due to their visual and auditory impact, they are good for reducing background noises and imparting a cooling effect on hot summer days. Before you buy a pump bear in mind that you will need approx 500gph of flow for every 6” of waterfall width to give you a respectable rate. Also don’t forget that a pumps output (head) declines rapidly the higher from the waterlevel it has to go, there is usually a chart on the side of the pump box. Pipework should be the correct bore for the pump, check it. Too narrow and it can cause excessive back-pressure on the pump impellor.Not good.

For small ponds with a low fish density and adequate planting a small fountain pump with a built in small sponge filter is adequate, if a little laborious to maintain. In this situation a solar pond pump may be an ideal choice. This can easily be set up in the middle of the pond with a fountain or geyser nozzle or maybe a poolside ornament jetting back in. Its good for oxygen exchange in the pond and also removes large debris from the water to a certain degree.

For a larger garden pond, perhaps containing larger fish a more heavy duty option is required. Consider purchasing an external koi pond pump, its an economical and practical solution for moving large amounts of water. If you are using a submersible pump site it in the deeper end of the pond, as far from any water returns (falls/courses) as possible to maximise circulation. Raise it up on a couple of bricks so it doesn’t keep sucking up sediment and clouding the water. When connecting to a pressurized or gravity return external pond filter keep the piping as direct and short as aesthetically possible, it will help to reduce back pressure on the pump and maximise flow. Look to turn over the entire volume of pond water every hour and a half, so if your pond was say 650 gallons and the inflow to your external filter was 24” above the water level, you need a pump that will give you at least 975gph at a 2ft head and you could return it to the pond down a 12” wide watercourse. You may also need a pond air pump if your pond is highly stocked or is very deep.