Whether you have a preformed or a liner pond, a pond pump is a paramount component of any water feature. Stagnant bodies of water attract mosquito infestations, which are a nuisance, and also undesirable, due to the recent outbreaks of the West Nile virus. Therefore, it is paramount that you utilize a pond pump that circulates your body of water.
Pumps are available in both submersible and external (out-of-pond) models. For the smaller pond (up to 1000 gallons of water), a submersible pump is the more economical and practical option. Submersible pumps can be placed directly in the pond and require relatively little installation. They are free of distracting noise, and for smaller ponds, can easily be utilized to drain your pond (if you hook up a hose to the output flow).
In the old days, the main disadvantage of submersible pumps was that the pump seal could rupture and release oil coolant into the water. However, this is not the case nowadays, because newer pumps are magnetic-driven, and no longer require coolant. "Mag-driven" pumps are slightly more expensive, but they have the added advantage of consuming less electricity.
Pumps are sized by gallons per hour (GPH) output at one foot of lift or height. Manufacturers usually offer charts that break down the power of each size pump according to incremental heights of one foot. It is recommended that you circulate your body of water at least once every 2 hours. Therefore you will need to size your pump to ensure that it has half the GPH rating as the volume of your pond in gallons. For example, if you have a 1000 gallon water feature, you will require at least a 500 GPH pump.
Calculating the proper pump for waterfalls is a bit trickier, because you must estimate your waterfall's height. To do so, you must measure the vertical height from the top of your pump to the top of your waterfall. In addition, you must add another foot of height or lift for every 10 feet of hosing you will be using (this will allow for loss of volume from resistance within the hose). To calculate the required pump GPH, a general rule of thumb is that each inch of width of the channel will require an extra 100 GPH. For example, if your stream or waterfall spillway will be 10 inches wide, you will need a pump that produces an excess flow of 1000 GPH at your waterfall's height.
If you plan on having fish, your water circulation demands will be drastically increased. Fish rely on the oxygen in the water to survive, hence a proper pump for a fish pond must ensure that extra oxygen is both introduced into the pond, and distributed throughout the pond. The general rule of thumb is that you must double your pump GPH if you plan on raising fish. An example of a pump that would be appropriate for fish is GardenSuperMart's UltraFlo line of pumps. These pumps have oxygen intake valves and an unique air/water air mix system which effectively increases the oxygen concentration in your pond.
The advantage of GardenSuperMart's low-maintenance, magnetic-driven UltraFlo pump kits is that they contain a sealed unit with a large enclosure that prevents debris from clogging the water intake. The UltraFlo line of pumps starts at 200 GPH, and increase up to 660 GPH. All UltraFlo pump kits come complete with a telescopic riser and diverter and 3 fountain heads.
If you require a more powerful pump, GardenSuperMart also has a SuperFlo line of pump kits that can provide up to 1585 GPH. All SuperFlo kits come complete with a telescopic riser and diverter, 4 fountain heads, and a sponge pre-filter. An optional SuperFlo Mechancial and Biological filter can also be added to the pump to provide additional water filtration for your fish.
Both the SuperFlo and the UltraFlo pumps can be purchased online at GardenSuperMart's store, www.buypond.com. In late May 2005, GardenSuperMart will also introduce a new line of MaxFlo waterfall pumps that can provide up to 2780 GPH of pumping power. Please stay tuned for further news and details.
Gerry Fung is the Vice President of GardenSuperMart, http://www.GardenSuperMart.com.
More information about their pond pump lines can be obtained at http://www.gardensupermart.com/buypond/c230094.2.html