You have to consider more than the design or style of your pump when choosing one for your fountain or pond. You should select a submersible fountain pump according to how much water the fountain holds and lifts. Most ponds and fountains use the simplest submersible pump, designed to circulate 50 gallons per hour or less. Water features such as waterfalls and fountains require a taller, more powerful pump. It is crucial to determine the height of the head and the lift of the fountain pump when sizing it.

To ensure your fountain or pond works properly, choosing the right pump is essential. Static water, algae growth and mosquitoes can result from failing to circulate the water properly. In order to keep your pond healthy for fish and other aquatic creatures, you must make sure the oxygen levels and nutrients are distributed evenly.

Choosing the right pump for your outdoor pond requires you to understand two terms.

Gallon-per-hour (GPH) and horsepower. Pond aeration is guided by the GPH metric, which is usually used for fountains. Your main concern should be the horsepower rating. Are you interested in a tall fountain spray and what size pond do you have? Pumps for pond fountains range in horsepower from 1/3 to 5 horsepower. We have a complete guide and chart to help you determine what size fountain you need.

In the case of large ponds or lakes, the fountain or aerator size must be determined differently for ponds and lakes that are 3 acres or more.

A half-acre pond should have a fountain with a least 1/2 horsepower. Smaller fountains may be possible but are not recommended. Visit our site for a detailed guide and chart on choosing the correct size of the fountain for your pond or subsurface aerator.

Bottom pond aeration with diffused air has the primary purpose of oxygenating the water.

Healthy pond ecosystems utilize dissolved oxygen for a wide range of functions. It’s not just your fish that require oxygen to survive, but also the bacteria that break down and eliminate toxins and organic debris. The primary healthy microorganism of a pond cannot function at its maximum potential without adequate oxygen in the water. If the pond is not healthy and clean, what does it mean? 

When dealing with shallow ponds, diaphragm air pumps are recommended. They are quiet, easy to handle, and much more convenient. The air must be forced through the tubes that are buried deeper in the pond with the help of an air compressor pump.

Choosing the right waterfall pump or pond pump comes down to how wide your flow of water will be.

The pond pump needs to be able to pump 100 gallons per hour for every inch of stream width or waterfall sheet. For example, if your waterfall is three feet high, your pond pump should be able to pump 100 gallons per hour at three feet.

Fountain Pump Selection

Pumps circulate the water through a filtration unit, spitter, or waterfall, like the heart of your pond. Your water feature will appear its best when you select the correct pump. Consider these factors before shopping:


Do you want some water to cascade over a waterfall, run through a UV clarifier, or run a small fountain?

  • A smaller pump is usually needed for fountains or spitting fountains.
  • Calculating the size of a waterfall requires a little more work. 
  • The pump size recommended for UV clarifiers or pressure filters varies.

Minimum Pump Size

Ideally, the water should be circulated through the filter at least twice an hour. If your pond contains 1,000 gallons, you’ll need a pump that can produce at least 500 gallons per hour. If you have fish, double the capacity of the pump to ensure clean water. It is a common misconception that pump size is determined by pond size alone; however, the size of waterfalls, streams, and fountains determines which pump will work effectively for your feature.

Measurements Needed

Depending on the desired flow rate and the pressure at the head, you will require a different pump. Head pressure is the amount of friction created when moving water uphill or across a long distance. How much water passes through a water feature depends largely on its flow rate. The following tips will help you calculate this:

  1. It is calculated by combining the vertical distance from the water surface to the waterfall top and the length of tubing. As 1′ of head pressure is equal to one foot of vertical height or 10′ of tubing, so is one foot of vertical height. As a result, a 3′ high feature with 16′ of tubing will have a 5′ high head pressure.
  2. In a waterfall, there is approximately 1,500 gallons of water flowing per foot. The pump would need to run at 3,000 GPH to power a waterfall 2′ wide. You can calculate your flow rate using 2,000 gallons per foot if you need a heavier flow.
  3. You may have noticed that we list different flow rates for our pumps, so it is simply a matter of matching up the numbers. A pump that can deliver 4,000 GPH at a head pressure of 5′ would be needed for an example requiring a heavy flow. 

Types of Fountain Pump

Submersible pumps and external centrifugal pumps, also known as out-of-pond pumps, are the two most common types of pond pumps. Each pump offers unique advantages depending on the application.

Submersible Pond Pumps

At the deepest part of a pond, submersible pumps should be completely submerged underwater. A skimmer box or pond vault is placed directly into your pond. Pumps with submersibles can move 50 gallons per hour to 5,000 gallons per hour. Smaller ponds (up to 1000 gallons of water) can benefit from these pumps because they are easy to install and less costly. They can also be used to drain your pond. There is a risk of the seal on the pump breaking, which can lead to oil spilling into your water if you have fish or other aquatic life in your pond.

Centrifugal Pond Pumps

Pumps for ponds are available on the market that is external or centrifugal. These pumps are placed adjacent to your pond. For ponds larger than 1000 gallons, external pond water pumps are appropriate. The noise and complexity of installing them compared to a submersible pump are both disadvantages.

The length of the cord on pond pumps is an important consideration when choosing one. Connect the cord far from the water and through the pond to ensure that it is long enough to go through. Water features must-have outlets at least six feet away from the water according to some electrical codes. Electrical extension cords are not recommended. For outdoor use, however, make sure it is plugged into a ground fault circuit interrupter (GFCI) so that it will shut off immediately in case of an overload.

How to Size a Fountain Pump

The size of a pond pump is determined by its GPH at one foot of lift or height. The performance of larger pumps is measured by horsepower. Calculate how much water there is in your pond first to determine the appropriate size pond pump. Multiply the length, width, and average depth by 7.5 in order to calculate the volume of water.

Water Circulation Factors

A minimum of once an hour must be spent circulating pond water. You need a pump that can run 500 gallons per hour at the top of the discharge if your pond is 500 gallons. You should turn the water in your pond at least twice an hour if it has a pressurized filter. A pond pump able to pump at least 500 GPH is required for a 1000 gallon tank. You should turn your pond water once every hour if your pond has a skimmer, waterfall, or both. For example, a pump rated for 1800 GPH is necessary for an 1800 gallon pond.

Calculating Head and Lift Height

A pond or fountain pump’s maximum lift capacity and head height rating are two of the most important measurements. Water is raised above the surface of the pond by the pump’s head height. Typically, pond fountain pumps can raise water up to a maximum head of water. This is referred to as “Maximum Head” or “Max Head”. Water is measured directly above the “Head” from the water’s surface. Your fountain’s lift can be calculated by measuring the distance the water has to travel from its pump location to its top, where the water comes out. It is crucial that you select a pump that has a lift greater than that measurement. As an example, if the pump needs to lift at least 36″, then that distance would be 24″. Water can be lifted to a maximum height by the pump if the maximum lift is specified.

Selecting the Proper Pond Water Pump Tubing

Choosing the right tubing size is also important because it directly affects the pump’s lift capability. Your pump’s maximum lift and the amount of water circulated will be limited if you use tubing less than specified.

The right pond or fountain water pump should be carefully chosen after doing a little research ahead of time. You will be able to keep your water clean and healthy, as well as your pump working efficiently if you follow these simple steps.