Good day all and welcome back to the wide world of pond biology!
There are many different strategies of aeration that we, as pond managers, have readily available to us. The strategy and type of system you pick truly matters in regards to how effective you will be at delivering oxygen throughout the pond biome.
If you are familiar with my other articles, you’ll know I am a HUGE FAN of pond aeration. Like….enormous – I have fountain pictures hanging in my bedroom and screech like a fanboy whenever new equipment catalogs are sent out. I’m that type of fan. There is no other investment that has a greater positive effect on a pond ecosystem than a properly sized aeration system. The benefits are many: a good air system can rehabilitate ponds, maintain good ponds and guarantee good health and condition of our scaly fish friends.
Each of these strategies will benefit any pond regardless of the pond’s size. Choosing the right one for your pond will maximize your investment’s impact on your pond’s ecosystem.
Below are the types of pond aerators that are easily available today.
Surface Aeration / Agitation: For ponds 6 feet of depth or shallower:
Floating aerators are very simple devices. They are motors suspended under a float with a propeller. These motors pump water from beneath the float up into a churning frothy mass a foot or so above the float. These types of units have been an industry standard for fish hatcheries and wastewater treatment ponds for 40-50 years. These units have the BEST oxygen transfer potential of any of the aeration systems here in this article. If you need a bunch of dissolved oxygen in your waterbody now, then surface aeration is a great choice.
Surface aerators do have some limitations in a residential setting. The units pull water from directly beneath the float, so they will not mix an entire waterbody greater than 6ft in depth. You will have the benefit of the O2 mixing into the top layers of water, but it will not reach the bottom sediments of deeper ponds, where most pond issues originate.
They are not super pretty either… Not exactly poster material for my room…. ahem.
1.5) Water Circulation using Water Movers / Pond Circulators:
Operating on the same principle as the above surface aerators, circulators are mounted horizontally under a float or attached to a dock to turn in oxygen by creating current. This current de-stagnates water and allows for a much enhanced ecosystem in the surrounding area where the turned in O2 is present. These units also work to clean up shorelines, channels, lagoons, and marinas by moving collected debris and algae away while turning in the air that will enhance the local ecosystem.
These are excellent for boat docks on lakeshores with accumulated muck.
Aerating Fountains: For ponds 6ft of depth or shallower – and – for decorative effect:
The dual-purpose workhorses of the fountain industry, aerating fountains are the most popular units in the aerating world, and for good reason. These fountains work two ways to help your pond.
- Good water flow creates the mixing action that aerates the surface waters down to 4-6ft of depth.
- Fountain produces a nice cone-shaped pattern, so you have something pretty to look at.
These units do not have the aeration output of a surface aerator because they deflect water around a disk to make the pattern you see. That small amount of pressure decreases the total volume of water that can be pushed through the float tube, therefore reducing the total pond water volume mixed in any given time frame.
This is why decorative fountains are not on this list… They are the Kardashians of the fountain world…. all pretty and flashy… not a lot of substance.
The high pressure water needed to make those fantastic patterns produce bupkis in the way of pond aeration. It is not zero, but the amount of mixing action is a small fraction of all the other strategies listed here.
Stating that, aerating pond fountains are great solutions for retention ponds or areas where you as a homeowner want to enjoy the look of your investment as well as the ecological benefit of aerating the pond.
Aerating fountains can also serve as excellent large pond fountains. They look nice, you can install LED lights to enhance their appeal, and they benefit your pond by turning in a good deal of O2.
Deep Water Diffused Aeration: Aeration for ponds deeper than 8ft
For ponds that are deep enough (8ft or >), diffused aeration is the strategy that will work the best for total pond remediation, nutrient control, and algae reduction. This aerator for ponds consists of an air compressor in a cabinet on shore with 1 or more airlines running into the pond attached to diffuser heads. From these diffuser heads bubble millions of tiny bubbles……
……… which diffuse oxygen into the water column and pull water from the bottom of the pond to the top. These systems are very effective at mixing the entire pond’s water volume without anything floating in the pond.
They are usually more affordable than fountains as well.
Sizing these systems is key to success. Your pond’s features will determine the number of diffusers you need for an appropriately sized air system.
Pond characteristics to consider when sizing your subsurface aeration system are:
- Pond shape
- Maximum and average depth
- Surface area
- Presence of islands/peninsulas
- Watershed features
EXAMPLE 1: Round Pond – 15ft max depth, 0.75 acre = A single diffuser will work great.
EXAMPLE 2: Round Pond – 8ft max depth, 0.75 acre = 4 diffusers are most likely appropriate.
As ponds age, they need more attention from us as pond managers. A good aeration system will slow the aging process and renew older ponds to a younger and more aesthetically pleasing state. These healthier ponds need less overall maintenance and can grow big healthy fish.
Thank you for taking the time to read through this article. Please contact me anytime for pond advice or to ask questions about the above aerators (or any other pond questions you may have). Get outside and enjoy your pond!