Pond Pump Size Calculator

We offer this pond size calculator to determine your pond size and in order to estimate energy costs. First, some notes of explanation:

For Ponds up to 7 Feet Average Depth Use a Surface Fountain or Aerator

When a pond is less than 6 or 7 feet in average depth, you only need to calculate surface acreage (length x width). Surface aerators are fountains or aerators only (no display) that float on the surface of your pond, rising and lowering with changes in water levels. A surface acre (one square mile) = 43,560 square feet. thus, a 100′ by 200′ pond is a little less than 1/2 surface acre. To calculate you merely multiply length x width or take the measurements and use our calculator.

For Ponds Over 7 Feet Average Depth

When ponds are over 7 feet in average depth, you will need to know length x width x average depth. Estimates are fine; you do not need to be exact. To calculate an acre foot
you will need to know length x width x acre feet. An acre foot is 1-foot deep x 1-surface acre in size. Surface aerators cannot reach far down into the water, so you will need to use bottom aeration.

What Size Pump Do I Need for My Pond?

Before you can determine the pump size for your pond, you need to choose which kind of fountain you will be using. Fountains vary a great deal, one model from another, one company brand from another. And horsepower is often only a rough gauge of what you need to know. You really need to know how much volume of water is being dispersed out of the nozzle. The design of the nozzle and pump are both going to affect the volume of water circulating in your pond. As a general rule, with a nozzle produced very tall displays small holes are used and these small holes restrict flow from the pump. Also, some pumps use impellers and some use propellers, and the difference between them is dramatic.

Decorative (Dramatic Display) Fountains

Decorative (Dramatic Display) Fountains 

These fountains offer the most appealing displays, but the volume of water pumped through the nozzles differs dramatically from model to model and brand to brand. Remember, it is volume of water traveling out of the nozzle that determines aeration, not the volume of water a pump produces before being restricted by a nozzle. Decorative fountains use impellers.

Aerating Fountains (V-shape display only)

Aerating fountains provide more aeration than decorative fountains do, as they use a propeller instead of an impeller and the propeller produces a V-shape pattern only with little restriction.

Aerating Fountains
Surface Aerators

Surface Aerators

Surface aerators also use a propeller, but they offer no display at all without any restrictions on the volume of water being circulated.

Bottom Aerators (Diffuser Systems)

Bottom aeration for ponds over 7′ deep don’t use a fountain pump. Instead, a compressor is housed at the shoreline to pump air into the pond though a diffuser or series of diffusers.

Bottom Aerators

Kasco is the number one company for providing accurate accounts of aeration, as their units’ flow rates are independently tested in sophisticated test tanks. Independent testing is the way to find out how much volume is actually being pumped.

Understanding how much aeration is needed for your pond and the best aeration system will keep your pond healthy on top of being pretty. You can learn more about pond fountain pumps here. 

What Size Do I Need?

Kasco offers the following recommendations for their units only:

Decorative Fountains  2 HP motor/surface acre of water
Aerating Fountains 1.5 HP motor/surface acre of water
Surface Aerators 1 HP motor/surface acre of water
Bottom Aeration For most ponds, a 1/4HP compressor with a single diffuser will work, but it’s best to call for assistance.

Again, these are calculations to be used with Kasco products, and for other brands you will often need much higher horsepower to achieve as much aeration.

Our pond pump size calculator can help you determine what water feature pump will work most efficiently while saving you money on your utility bill. Contact us for more information. 805-928-7410

Pond Size Calculator
Electricity Calculator

Because we get questions about watts and amperage, we have added the two calculators below. If you know watts and voltage, you can calculate amps. If you know amps and voltage, you can calculate watts.

Watts to Amps Calculator
Amps to Watts Calculator