If you’ve ever seen a slimy, algae-covered pond up close, it isn’t exactly the best example of natural beauty. In addition to the smell and the degraded water quality, algae reduces oxygen production by preventing sunlight from reaching the bottom of the pond.
The solution is just as simple as it sounds—add oxygen.
The main difference between a pond fountain and a pond aerator is their intended purpose.
Pond Fountains are meant to be decorative, and any benefits to the water quality are secondary. With a pond aerator, the main objective is to add oxygen, reduce the number of insects, and prevent algae from accumulating.
Pond aerators can be broken into two categories: surface and sub-surface. Installing a pond aerator is an excellent choice for the following applications:
- Clearing a pond with significant existing algae
- Improving water health for fish or plants
- Reducing smells and odors
Surface aerators draw water to the surface and pump it into the air to gather oxygen before it returns to the pond. This process circulates the water, mixes different temperature layers within the pond, and generates a current to keep debris away.
Sub Surface Aerators
Sub-surface aerators rely on a compressor that pushes air out of an attached line and into the water. The bubbles rise and break the surface of the water, which allows oxygen to enter the pond.
Sub-surface aerators can also improve circulation and allow oxygen to reach deeper areas. These aerators can work with a broad range of pond sizes and even run on solar power.
Pond fountains put aesthetics first and come in a wide variety of designs. Fountains are best for these applications:
- Visually enhancing a pond
- Adding pleasant background noise to create a peaceful environment
- Providing some aeration and circulation
- Lighting an area or adding a light display
Fountains operate the same way as surface aerators, with water circulating from the bottom and spraying into the air to collect oxygen. The water breaks the surface as it falls to allow more oxygen that way as well. The level of aeration will vary based on the exact design.
Choosing the Right Aerator or Fountain
Many factors play a role in determining the right aerator or fountain for a specific pond. Making a selection often requires balancing several considerations at once, including cost, maintenance, and horsepower.
In general, fountains are more expensive than pond aerators because they rely on stronger pumps to move water in a decorative pattern. Depending on the size of the fountain, daily operating costs can be over $10 per day.
Because of this, and the potential associated maintenance costs, many people will only run their fountains part of the time.
Aerators, on the other hand, are much cheaper to operate. Even models intended for larger ponds can run for less than $3 per day. Since more aeration is better for the water quality, these can be used around the clock for much cheaper than a fountain.
Another option is to consider solar power. Solar power tends to have a higher upfront cost, but lower operating expenses going forward. During periods of higher energy prices, Solar Pond Fountains and Aerators can offer significant savings.
Fountains and surface aerators require more general maintenance and cleaning since they draw water from deeper in the pond where there may be muck or debris. This can repeatedly clog the intake screen.
Although motor assemblies are often sealed, they should be serviced every few years. Surface aerators are designed with submersible motors that don’t require oil, so no oil changes are needed during ongoing care.
Sub-surface aerators must also be cleaned whenever the intake filter becomes dirty. Filters can last up to a year, but air cleanliness around the pump can drastically reduce the time between filter replacements. Seals should also be checked every few years.
Pond Size and Depth
For fountains and surface aerators, a common recommendation is to have 1 HP for every surface acre of pond to maximize aeration. Horsepower can run from 3/4 HP all the way up to 7.5 HP for a resulting spray of approximately 9 feet and 26 feet, respectively.
Small sub-surface aerators of only 1/4 HP can accommodate ponds of up to an acre based on installation depth.
For especially large ponds, multiple diffusers may be needed to provide full coverage.
Shallow ponds will require more diffusers since each will be less effective at the reduced depth.
The Scott Aerator DA-20 Display Aerator is a nice combination pond aerator and pond fountain.
Depending on the size of your pond, the DA 20 is available in multiple horsepower sizes that range from 1/3 horsepower all the way up to 3 horsepower. The larger the pond, the higher amount of horsepower you will need.
In terms of height, the 1/3 horsepower offers a 5 foot fountain spray height and the 3 horsepower unit provides an 11 foot fountain spray height.
The high flow rate provides an impressive water display while also clearing algae, keeping away insects, and oxygenating the pond. Over time, the improved water circulation and aeration will loosen the muck at the bottom of the pond for cleaner, healthier water.
The DA-20 model comes with an oil-free submersible motor made of stainless steel. Since no oil is involved, oil changes aren’t required, and there’s no risk of exposing fish or plants to accidental spills.
Most importantly, the DA 20 does not require winterization. You can leave the DA 20 in the water year round, even during severe winter weather.
The Amherst Fountain boasts a flow rate of 75 gallons per minute to produce three separate tiers of water that reach over 35 feet in height. The water cascades in layers to the pond below, creating a ripple effect that perfectly complements the majestic, timeless style.
The smallest sized Amherst fountain starts at 1 horsepower and the largest sized option is the 3 horsepower sized unit.
Optional Fountain Lights are also available with the Amherst.
The North Star Fountain Aerator is a beautiful fountain and pond aerator combination. This option provides you with a nice visual fountain display for your residential or office park while also providing aeration for your pond or lake.
The Northstar is suitable for ponds as small as an eighth of an acre. Yet with a flow rate of 600 gallons per minute and the durability to withstand even subzero temperatures, the Northstar packs major features in a smaller sized unit.
The North Star Fountain Aerator has optional lighting and a trumpet-shaped water pattern for a visual enhancement with powerful aeration.
Browse our selection of small pond fountains with lights for more fountain ideas for smaller sized ponds.
We also offer a guide for How to put a Fountain in a Pond.