How To Choose the Right Size Pond Pump Fountain or Aerator

Choosing the right sized pond pump fountain or aerator can seem like a daunting task, especially if you’re just starting your fountain search. Properly aerating your pond’s water with a pump keeps it healthy. It’s an important piece of an overall pond health strategy, and with a little bit of our help, you’ll have a great idea on which pond pump size suits you best. 

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Knowing What Pond Pump Options You Have

When it comes to circulating your pond’s water in a healthy way, you have a couple options. 

Stainless Steel Fountain Pump in Pond

Floating Pond Fountains:

A floating fountain is the most beautiful way to aerate a pond or lake. Seeing water cascading on the surface of your pond is very pretty and the sound is soothing. The chart we created below gives you a quick and thorough idea of which size pump you should choose. 

Pond aerator in tranquil blue pond

Pond Aerators:

A pond aerator is similarly beautiful to a floating fountain, but it is able to move significantly more water per hour. Water does not enter the motor, similar to a boat propeller. Consequently, aerators don’t have different spray patterns. 

Sub-surface aerator working in pond

Sub-Surface Aerators:

These aeration systems work from the bottom of your pond. There’s nothing flashy about them, but they do a great job of getting the stagnant water at the bottom of your pond moving. You can find one of these systems at a good price from a company like Discount Pond Shop.

What is the Difference Between a Floating Pond Fountain and a Pond Aerator?

What is the difference between a pond fountain and a pond aerator?

We get asked this question all the time, and yes, there is a significant difference between a floating pond fountain and a pond aerator! Simply put, as the name would suggest, a pond aerator is much better at aerating. It pumps a considerable amount more water per hour than a floating pond fountain. 

Floating Pond Fountains

Most lake and pond fountains are designed with a pump that is usually either a high-volume waterfall pump or an energy saving asynchronous pump. The pump forces the water through a decorative nozzle, and that is how you get the pretty fountain displays. A floating pond fountain will give you high and decorative displays. This type of fountain will also aerate your pond, but at a lower rate. Any time you move the water you are interrupting stagnation, slowing the growth of algae while adding oxygen.

Pond Aerators

Unlike floating pond fountains, pond aerators need to move high volumes of water in order to accomplish the following tasks:

  • Effectively aerate the pond or lake by moving as much water as possible while refreshing the stagnant pond water (destratification).
  • Improve the landscape or waterscape with its visual appearance, and also with the tranquil sound of the splashing water from the plume spray.
Pond aerator outside a business

Decorative pond aerators use heavy duty, all stainless-steel motors that rotate a high-quality propeller that is also made of stainless steel. It works very similar to a boat propeller. Water does not enter the motor and the propeller throws an extraordinarily high volume of the water into the air. Therefore, there is no pump or nozzle to clog or any small pipe outlets to obstruct.

While most 1 HP fountains can only pump 8,000 gallons per hour, one of our 1 HP display aerators can move an astounding 30,000 gallons per hour into the air. A 2 HP fountain can only pump 15,000 gallons per hour, while a 2 HP decorative aerator can move an astounding 34,000 gallons per hour into the air.

Properly Aerating Your Pond

In addition to their aesthetic qualities, fountains and pond aerators add a lot of oxygen into the pond as the tiny droplets make contact with the air and bring it back into the pond. Do pond water fountains provide enough aeration?  Determining if a fountain is right for your pond will depend on the depth, shape, and size of your pond.

The 6 Foot Rule

If your pond is more than 6-7 feet deep, a fountain will not provide enough aeration, because the fountain cannot mix the deeper water with the surface water at the same time. The deeper water remains untouched and oxygen-deprived.

Subsurface aeration systems, like the Bubble-Pro supplied by Discount Pond Shop, are recommended for deeper ponds to provide complete aeration. The air is pushed through air tubes and a diffuser that is positioned at the bottom of the pond. The air bubbles rise to the surface, oxygenated water then moves to the bottom, creating a healthy ecosystem.

Green forest with a pond aerator working

Fountains 2 Go Insights

All ponds need aeration, but if your pond is fairly clean, and you prefer a fancier display, we recommend a floating pond fountain. If your pond has problems with algae and aquatic weeds, or is stocked with fish, we recommend looking into a non-clogging pond aerator. You will still have a lovely water display but will have much greater aeration.

If you’re looking for the best of both worlds, we recommend investing in a floating pond fountain for the prettier display. Then supplementing that with a sub-surface aeration system that pumps a high volume of air into the bottom of the pond. You can place the fountain in the middle of your pond, and run two air lines from the air pump on each side of the fountain. 

It is best to remove fountains for the winter so they do not get damaged during icy conditions, so your fish would be without pond aeration for the winter. Additionally, a fountain can get pretty costly when you are operating it 24/7.

A sub-surface aeration system is designed to be used in the winter months. It is more affordable and has lower operating costs. This photo illustrates a pond in the winter months benefiting from a sub-surface aeration system.  

Sub-surface de-icer in icy pond

The Shape of a Pond

Aeration is restricted in ponds with irregular shapes, like oblong or with coves. The oxygenated water created by a fountain won’t reach those isolated areas of your pond. Multiple pond water fountains or a combination of a fountain and sub-surface aeration system may be needed for proper aeration.

Something to keep in mind: over-aerating your pond is not a bad thing. But under-aerating causes algae blooms and is the cause of many pond problems. If there’s any doubt that you’ll need more aeration, it’s recommended to get a bigger aerator or fountain. 

Real Customer Examples

Sizing up your pond in your backyard alone can be overwhelming. There seems to be a lot of factors that could weigh in to picking a properly sized pond pump. The depth of your pond, size, and shape are all factors. Does your pond have fish? These are questions you’ll have to ask yourself. With a few customer examples, it will be much easier to decide what route you’d like to take for your pond! 

Example #1 comes courtesy of Roger living in Missouri

Here, you can see our 1 HP Stainless Steel Pro Series fountain kit placed in a 1/2 acre pond. In this specific example, Roger doesn’t have fish in his pond, but it isn’t completely circular. This pond is less than 6 feet deep and would benefit from an aerating pond fountain.

If he were to go by our size chart, Roger could get away with using a 3/4 HP fountain. Due to the irregular shape of his pond and a desire to get a fountain that was a little more impressive, Roger went with a 1 HP fountain. We think it looks pretty good!

Example #2 Elaine from Florida

Elaine purchased our 1 HP Classic Pond Fountain Pump for her 2/3 acre pond. It has a maximum depth of 6 feet. As you can see from the picture, her water is looking very healthy. Which makes sense, because a 1 HP fountain is exactly what we’d recommend for her pond’s size. 

We received a phone call from Elaine a couple days ago, as I’m writing this in September of 2020. They were hit by a hurricane that knocked the tree in the picture down. What you can’t see in the picture, is that the tree had actually hit the fountain and initially it had looked as if the impact had broken it. She had the fountain set up with a timer, and hilariously, the timer turned the fountain on while the tree was laying on top of it. She called to let us know how durable she thought the fountain was, even after having a tree smash down on it!

Pristine pond with a pond fountain surrounded by forest

How to Estimate a Pond or Lake Size 

Below you can view the actual calculations we use to determine pond size. If you would like to use one of our tools, check out our pond calculator!

In feet, measure length (L), width (W) and average depth (D). Then multiply for:

Square shaped bodies of water: 

L x W x D x 7.5 = Approximate Gallons

Circular or elliptical bodies of water:

L x W x D x 5.9 = Approximate Gallons

Total gallons divided by 325,851.6 (gallons per acre foot) = Acre Feet

Floating Pond Fountain Sizing Chart
Floating pond aerator sizing chart

We love helping! If you have further questions for us after reading this article, please give us a call! 

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