A properly sized pump will ensure the well-being of a pond’s aquatic life, optimize its beauty and keep utility costs down.
The first thing to consider when selecting a pond pump is whether it will be used primarily for a waterfall, fountain display or for filtration and recirculation.
Fish pond pumps are often required to perform at a higher capacity than fountain pumps while waterfall pumps must be sized according to both pumping capacity and waterfall height.
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Video used courtesy of Living Water Aeration
Selecting the Right Pond Pump
Because all pond pumps are sized in gallons per hour (GPH), knowing the volume of water in your pond is key to ensuring adequate circulation.
Insufficient circulation can result in stagnant water and an environment unable to sustain fish and plants.
As a general rule, pond water should be circulated about once every hour. Consequently, a pond containing 500 gallons requires a pump rated at a minimum of 500 GPH.
Total pond gallons can be determined by connecting a water meter to a garden hose while initially filling the pond. To calculate the approximate volume, multiply the pond’s length in feet x width in feet x depth in feet x 7.5.
In addition to circulating water, pond pumps are often required to lift water.
Head height is the vertical distance the pump must raise water above the surface of the pond. The greater the head height, the harder your pump will have to work. To determine your head height, calculate the following:
A = The vertical height from the top of your pump to the top of your water stream.
B = Total feet of tubing connecting the top of the water stream to the water filter.
C = Number of 90 degree bends and reducers.
D = Number of filters and miscellaneous adapters you will be pumping water through. (Both C & D put additional pressure on the pump.)
Plug your pond’s coordinates into the following formula:
A + (B / 10) + (C / 2) + (D / 4) = Approximate Head Pressure
A = Vertical Height = 4’
B = Total Distance = 8’
C = Number of 90 degree bends and reducers = 2
D = Number of misc. adaptors = 6
4 + (8 / 10) + (2 / 2) + (6 / 4) = 7.3 Total Dynamic Head Pressure
Most pumps are sold with flow charts illustrating how they perform across a range of measures.
Other factors to consider when choosing a pond pump include.
Width of Spillway: In waterfall applications, 1 inch = 125 GPH.
Fish Load: In fish pond applications, maximum fish load is approximately five inches of fish per five gallons of pond water.
Voltage /Energy Consumption: Because pond pumps are designed to run constantly, every watt will add substantially to utility costs.
POND PUMP TYPES
Magnetic Drive Pumps are the most energy efficient pond pumps and, though costlier than direct drive models, they quickly pay for themselves in utility cost savings. Magnetic drive pumps are oil-free and therefore safe for ponds stocked with fish. They are not ideal for high head applications due to their limited ability to push water to significant heights.
Direct Drive Pumps are better-suited for powering water features with high head height. These motor-driven pumps tend to cost less than their mag-drive counterparts but require a substantial amount of energy to operate. Unlike mag-drives, direct drive pumps are often self-priming and will draw water to them.
Submersible Pumps are designed to run while quietly submerged in a pond. Their unobtrusiveness lends itself to naturalistic settings. Maintenance, however, can be inconvenient as submersible pumps must be periodically pulled from the water and cleared of debris.
External Pumps require less maintenance than submersible pumps and tend to have a longer life. They are often loud and have to be camouflaged but require less energy than submersible pumps, particularly in larger applications. A 6000 GPH external pump can run on 450 watts, where as a standard submersible pump generally requires 750 – 1200 watts.
When shopping for a pond pump for a stream or waterfall, bigger is better. Make sure its head capacity, or lift, is well above the height you've planned for your falls.
Check the pump cord length. Some codes require the electrical outlet for a water feature to be at least 6 feet away from water.
Consider purchasing two pumps at once. An extra pump could save your pond if your existing pump should fail.
For detailed specs, manuals and reviews of the pond pumps we stock and ship nationally, visit our product pages at www.pumpproducts.com or call us for details: 1-800-429-0800.