All About Pumps

All About Pumps for Backyard Ponds

Water pumps are used in backyard ponds to move/ recirculate water. Typically they move water through a filter to return to the pond, often over a waterfall or similar discharge point. They can also move water to power a decorative fountain or statuary, or simply recirculate water for aeration, sound, aesthetic effect, etc. It is best to use water pumps that are specifically designed for water gardens or koi/ fish ponds. This helps to assure good performance, ease of use and full warranty coverage. A few facts are nearly universal with all pumps designed for these applications.

Universal Facts

1) They require electricity.
Nearly all are standard 115 volt and come completely wired with 10-20 ft. cords (ready to plug in). There are some for larger applications that may require wiring and/ or require 230 volts. Some pumps may be wired for 115 or 230 volt, dependent on the specific situation/ application. Some pumps, due to design, are more energy efficient than others, ie; they will move more water greater distances using less power than other pumps As of the 2010 season solar powered pumps (at least reliable ones) are not readily available.
2) They have one primary moving part called the "impeller" and two "ports" (or openings) for intake and discharge of water. These pumps operate very simply with a motor that drives the impeller causing it to spin. (Picture a propeller on an airplane). The blades of the impeller are angled to move the water through the body of the pump, "pulling" the water into the intake port and simultaneously "pushing" it out of the discharge port. This discharge port (and sometimes the intake) accommodates attachment of piping/ tubing if desired.
3) They should never be allowed to run "dry" without some source of water allowed to freely enter the intake opening. The spinning of the impeller creates friction which in turn creates heat. The water passing through the pump acts as a coolant for the pump's motor keeping excessive heat from damaging it. The longer a pump is allowed to run without water the greater the potential for damage, long-term wear, or complete failure to the pump. Even submersible pumps in the water are subject to this if their intake is some how blocked and water cannot enter the pump body.
4) They are rated by G.P.H. (gallons per hour) or G.P.M. (gallons per minute). This is the amount of water the pump is capable of delivering through the discharge. This number varies for each pump based on the distance (vertically and horizontally) the water is moved through piping/ tubing attached to the pump. The higher/ further the discharge point is from the pump or intake point the less water is delivered. This is because the water is slowed by contact (friction) with the piping/ tubing inner wall, and obviously the effect of gravity lessens the flow quickly as water is moved vertically. Most pumps provide information on GPH/ or GPM flowrates per vertical height of discharge, and the rated maximum vertical distance. This information is critical in specific pump selection.
5) They provide years of service when properly maintained. This will vary from dependent upon model and application. Timely maintenance is key though, and with it one may expect 3-5 years of operation as average and 10-12 years is even possible. Most reliable retailers offer a one year warranty and some models have a 3 or even 5 year manufacturer warranty. Once the pump motor no longer works, ie; won't run or push the impeller, the entire pump must be replaced since repair is cost prohibitive.

Submersible Pumps

- A pump described as submersible means it is designed to operate underwater in the pond or skimmer housing. Note: Some submersible pumps can be operated outside of the pond as an "in-line" pump, (see below).

- A large majority of backyard ponds utilize submersible pumps mainly due to ease of installation, operation, and maintenance. The water acts to "muffle" the sound of the pump allowing them to operate virtually soundless.

- Almost all are black or dark colored to blend in with the pond floor. They come in a variety of shapes and sizes, and most are fairly compact rarely exceeding 15" in any dimensional measurement.

- Installation of a submersible pump into a pond is simply attaching piping/ or tubing (if desired), placing into the pond/ or skimmer and plugging it in. Note: Since most pump applications require them to run 24/7 nearly all pumps for backyard ponds are started/stopped by simply connecting/disconnecting the power cord. There are no switches on submersible pumps. Most are outfitted with or include a fitting, or fittings for connection of piping/tubing.

- The only maintenance required is to insure the intake of the pump stays open. This generally involves removing the pump from the water, removing, then cleaning the pumps intake protective device (anything from a small plastic screen to a large pre-filter) and the pumps intake port. Occasionally the impeller itself will become fouled with debris and require cleaning. Some impellers are removable for maintenance and/or replacement.

- They may be left in place all winter long, operating or not as long as they cannot freeze. Some newer pumps claim to withstand frozen water conditions, though it is still recommended to protect a pump in the winter. If they must be removed from the pond/ skimmer they should be stored in water to avoid damage parts drying-out. Some pond owners will remove their pump from the skimmer housing (shallow water) and simply place it in the pond (deeper water) to avoid freezing conditions.

Non-Submersible Pumps

- Sometimes referred to as "in-line" pumps these pumps are designed and made to operate out of water. These pumps cannot be submerged, and are designed to operate like swimming pool or spa pumps. They work to move large volumes of water, typically over 2,000 GPH, in larger ponds, typically over 1,000 gallon capacity. Recently these pumps have gained popularity due to more professional large pond construction, particularly koi ponds. They move the larger volumes of water needed in these applications and can be energy efficient.

- All of these pumps operate with a motor "sound" or "hum" and some are quieter than others. This should be considered when purchasing and placing these pumps.

- They come in a variety of colors and sizes. They are somewhat larger than most submersible pumps, though most would fit in a 12" x 12" x 20" long box.

- Installation of these pumps requires some knowledge or experience in basic plumbing skills since most of them come with threaded ports only and require the proper adaptors, fittings, etc. to be installed for connecting to piping (typically standard PVC hard-pipe). Basic electrical skills will be needed if the pump is not wired. A normal installation starts with an intake pipe connected to a drain / skimmer/ pre-filter or some point underwater. This is connected to the intake port on the pump. This distance may be anywhere from 3 ' to 50' or more dependent on pump location. The discharge port is piped to desired point(s). The pump location may be based on several factors, including overall installation design, sight constraints, sound considerations, etc.

- Most pond builders prefer these type of pumps to be "self-priming". These pumps will "restart" after stopping without water in the pump. "Self-priming" pumps can "pull" water from the source, while other pumps must remain full of water (including the entire intake piping) to "restart" after stopping. Pumps that do not "self-prime" must be positioned lower the ponds water level, while "self-priming" models can be located above water level of the pond. Careful consideration should be given to this issue to ensure ease of maintenance, operation and winterizing.

- These pumps are started/stopped via cord/plug connection or a wired switch. A few models have off/on switches.

- These pumps are maintained by ensuring the intake remains open and free flowing. A "strainer basket" (included with most of these pumps) should be installed at the intake port. These small plastic baskets will collect debris as it settles prior to entering the pump. The pumped can be stopped periodically to empty the basket. The intake point will require some attention/ cleaning periodically especially if a pre-filter or skimmer is attached. An "in-line" pump that cannot get water into the intake while running will quickly overheat and become damaged. Some pumps are made to be more thermally protective and will temporarily shut down when too hot, though it is never good to allow this to happen.

- There are no replaceable parts (typically) in these pumps.

- These pumps can operate and/or stay in place through freezing winter conditions. If not being operated the pump itself, (most have a drain plug), and all piping must be completely drained.