Subsurface Aeration is the most effective way to aerate large natural ponds. A subsurface aeration system not only increases oxygen levels in your pond, it also helps to greatly reduces organic matter and sludge buildup on the bottom – reducing nutrients, algae blooms and aquatic weeds.

But finding the right type and size of aeration system for your pond can be confusing. The size, depth and shape of you pond are all important factors in determining which aeration system will work the most effectively. Keep reading to see how we break down each of these factors and take the guess work out of picking the right subsurface aeration system

To learn more about the benefits of pond aeration, see our Aeration – The Key to a Clear Natural Pond page to see how aeration can improve your pond.

If you would like to have an aeration system installed in your pond, visit our Large Pond Maintenance & Installation Services page for more information.

If you are planning to install an aeration system in your pond, there are 3 important attributes of your pond that you need to consider to properly size the system.

1. Depth  

2. Area 

3. Shape

Often, the most overlooked factor to consider when installing a subsurface aerator is the depth of your pond. When considering an aeration system, ponds can basically be divided into 2 categories – shallow ponds and deep ponds.

Shallow Ponds – Ponds 6’ / 1.83 m and under are considered shallow ponds. In ponds that are 6’ deep or less, Shallow Pond aeration systems are the best choice.  Linear diaphragm and linear piston compressors are the 2 types of compressors typically used in shallow ponds. These compressors are energy efficient, reliable and produce large volumes of air, but they only work in a pond with a maximum depth of 6’ to 7’.  

Deep Ponds – Ponds over 6’ / 1.83 m deep fall into the deep pond category. At depths greater than 6’ / 1.83 m., there are 2 excellent options available. The most popular type are Rocking Piston compressors. They are very powerful, economical produce ample air flow and operate best at depths from 7’ to 50’. Rotary Vane compressors are becoming more popular for use in intermediate depth ponds from 5’ / 1.5 m to 16‘ / 4.9 m deep. These compressors are produce higher volumes of compared to Rocking Piston compressors, however they can’t be used very deep ponds and are more expensive.

The amount of circulation an aeration system creates is directly related to the depth of the pond. The deeper the pond, the more circulation is created.

The circulation is created by the rising air bubbles produced by the aeration system. As these bubble rise from the diffuser at the bottom of the pond, they pull water along with them to the surface. In deeper ponds, the bubbles must rise a greater distance to reach the surface creating more ‘pull’. The deeper the pond, the more water the bubbles can pull along with them.

The deeper the pond – The more effective aeration is

Here is an illustration of how depth affects aeration.

Let’s see how effective a ¼ HP Aeration System is in two different ponds. The diagram below illustrates how depth affects the effectiveness of aeration.

• For example – If you have a round shaped pond that is only 6′ deep,  ¼ HP Aeration System with 1 diffuser can effectively aerate an area of about ¼ acre.  If your pond much larger, but still only 6′ deep. a larger system with multiple diffusers will be needed.
• However, this same system can aerate a much larger pond if it is deeper.  If the pond is 15’ deep, this same ¼ HP Aeration System can aerate a 1 acre pond!

The shape of your pond also greatly influences the size and design of the aeration system.

Round or circular shaped ponds naturally lend themselves to effective aeration. In a deeper pond, 1 diffuser placed in the center of a round pond will often provide sufficient aeration. The bubbles rising from the diffuser produce a circular pattern once they spread out at the surface of the pond, creating ripples that radiate out to the edges of the pond. On the other hand, long, narrow ponds, or irregular shaped ponds often require 2 or more diffusers to effectively circulate the water in all areas of the pond.

 In the diagram below, the dotted circles represents the area that 1 diffuser will effective aerate. 

The circular shaped pond (figure 1) has 1 diffuser placed in the center of the pond, which essentially covers most of the pond.

The long, narrow pond (figure 2), needs 2 diffusers placed strategically in the pond to maximize their effectiveness.

The surface area or size of a pond is directly related to the size of the aeration system needed to properly aerate the pond. Simply put, if depth and shape are the same, a larger pond will need a larger compressor that produces more air to power multiple diffusers.

If your pond is basically round and you know the approximate dimensions, use our handy calculator to determine the surface area and volume.

Now that you have better understanding of what subsurface aeration systems are and how they work, you can take this information along with the measurements of your pond to determine what size aeration system is best for you.  

Example 2 – Circular Pond

Let’s say you want to know what size aeration system you would need for the circular pond in figure 3 above. It is 150’ in diameter and 16’deep. 

 You can use the chart below ‘Area Coveres by Single Diffuser’ to determine the correct system for this pond.

1. Find the corresponding depth of this pond along the top row of the chart – 16’.
2. Under the @16’ column, you can see that 1 diffuser will cover an area of with 150′ diameter. Which is exactly the diameter of the pond in figure 3. This tells us that an aeration system with 1 diffuser will effectively aerate this pond, as long as it produces an minimum of 1.5 CFM and can pump air to a depth of 16′. The best option ini this case would be a rocking piston compressor.