What Does a Pond Pump Do?

pond pumps

A pond pump is connected to the electrical supply and submerged at the bottom of the pond. It provides all the power to circulate the water through the filter, waterfalls, fountains, ornaments, and uv sterilizer units.

The proper pump and circulation system is very important for the ecosystem of your pond. Pumps that power filters and water features keep the water moving, providing the necessary cleaning of the water.
Waterfalls and fountains provide oxygen levels for healthy fish and plants and also discourage mosquito populations.

How Large a Pond Pump Do I Need?

A good rule of thumb for evaluating how large pond pumps should be to provide filtering-only is to choose a pump that will turn half the volume of the pond per hour. Therefore, if you have a pond whose volume is 1000 gallons, a pump that will pump 500 gallons per hour is adequate. (See How to Figure the Gallons In Your Pond)

Generally, the more features added to the system, the more powerful the pond pumps must be.
Also, restrictions such as bends in tubing, dirty intake filter, smaller diameter tubing than recommended, the height the pump must pump the water and any other less-than-optimum installation can inhibit the pumping capacity of your pump. Choose a pump model that offers a higher output than you think you will need.  Then install a ball valve on the outside of the pump so that you can adjust the flow up or down according to your needs.

If You Want to Use a Pond Skimmer

The best way to evaluate the size of the pond pump needed if you want to use a Pond Skimmer is to multiply the surface area of the pond by 10 to 15 times and use a pond pump with that many gallons per hour pumping capacity. [Πr2 or (3.1415) x radius of the pond2 x 15]

If You Want a Waterfall Feature

Waterfalls present their own challenges. You must keep in mind how wide the water fall is and how high. Be sure to check the "head" or pumping height rating on any pond pump you are considering. A waterfall that is 10 feet above the pond surface will require at least a 10 foot "head". It will need a pond pump capable of delivering that type of pressure. Pond Pumps deliver much less than their maximum gallon per hour rating when pumping at higher height (head). And longer pipe lengths or 90 degree elbows will increase the needed "head" measurement.

After you have decided how much water volume you need to "turn" for filtering, how much surface area you need to skim if you are going to use a skimmer, and how much head height you need for the waterfall(s), read the specifications on each pond pump. Choose the pond pump which delivers at least the minimum requirements for the most demanding activity for each feature.

Most pond owners choose a slightly more powerful pond pump than necessary, as it is less expensive to invest in a single pond pump than to re-invest if your needs grow with your imagination. Contrary to popular opinion, higher pumping capacity will not diminish the biological activity of the filter. If you choose a pump model that offers a higher output than you think you will need, you can install a ball valve on the outside of the pump so that you can adjust the flow up or down according to your needs as the features change.

Depending on the layout, in some cases, it may be advisable to use multiple pond pumps for multiple or larger streams, fountains, or for heavy fish loads.