Pond pumps are available in a wide variety of types, sizes and efficiencies. Choosing the right pump for your pond is one of the most important decisions that you will have to make and can be somewhat confusing. A pond pump is the “heart” of the Ecosystem Pond as it pulls water through the skimmer and pushes it up to the biological filter and adds necessary oxygen.
The two basic types of pond pumps are submersible and in-line. Submersible pumps are easier to install and maintain but do have the disadvantage of being non-repairable. In-line pumps can be repaired but installation is much more complicated since they require priming and need to be installed in a weather proof enclosure. We recommend high-efficiency submersible pond pumps installed in a pond skimmer and properly sized to achieve the necessary flow rate at the desired height.
When comparing pond pumps be sure to consider the lifetime cost of each pump. Low-efficiency pumps are cheaper to purchase but very expensive to operate. High-efficiency pumps are more costly to purchase but the cost difference will normally be made up within the first year of operation due to lower energy costs. High-efficiency pumps normally include a longer warranty period as well.
To size a pond pump you need to determine the required flow rate and the height at which this flow needs to be delivered. Recommended turnover rate is to circulate the total pond volume a minimum of once every two hours with a preferred rate of once every hour. Pond volume is calculated as Average Length x Average Width x Average Depth x 7.48 gallons per cubic foot. While this is an important starting point, we find in the majority of ponds the required flow rate to produce the waterfall and stream flow desired is even greater than that necessary for an hourly pond turnover. Minimum flow rate for a stream or waterfall is 1500 gallons per hour per foot of stream or waterfall width.
The next part of properly sizing your pond pump is to calculate the pumping height. This is determined by the difference in height from the top of pond level to the pump discharge level. Be aware that many advertised pump flow rates are the maximum flow rate at zero feet. The pump you choose must be capable of producing the required volume at the required height. To reduce friction loss the piping you use should be the same size (or next size larger) as the pump discharge.
True Pump carries a wide variety of pond pumps to choose from. We have many years of experience in pump sizing and will be happy to help you determine the best choice for your individual application.