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How to Aerate Your Pond to Keep It Clear & Healthy

Posted on November 24, 2021 
by Thomas VanAmerongen

Like every other living organism on earth, your pond’s inhabitants — including fish, bacteria and other wildlife — need oxygen to survive. So, if you want to keep your pond clean, clear and teeming with life, you need to make sure it is properly aerated.

A pond’s ecosystem can easily become unbalanced if there isn’t enough air in the water — various aeration systems can be used to add oxygen and help circulate your pond’s water to help keep it healthy.

Here’s some basic information on ponds and how you can aerate yours properly!

Close up of natural pond.

Ponds have three distinct layers

The water in the top layer of your pond is light and filled with oxygen, while the bottom layer is dense with very little oxygen. The layer in the middle is the transition layer which separates the top from the bottom.

This is known as water stratification and aeration circulates the water and provides uniform oxygen levels throughout the entire pond.

Aerating backyard pond.

Signs that your pond needs aeration

There are many signs that tell you that you need to adjust the oxygen levels in your pond, and some of them are hard to miss.

  • Fish will come to the oxygen-rich surface of the pond to breathe — they will appear restless and agitated.
  • Thick layers of algae will start growing on the water’s surface.
  • Your pond will start to develop a foul, brackish odour from decaying vegetation and organic matter.

One way to tell if your pond needs aeration before it gets to this state is to take the water’s temperature. The temperature discrepancy between the top and the bottom should be minimal.

Aerate your pond with aquatic plants

Plants add a beautiful aesthetic to your backyard pond — they also provide shelter for fish, help remove excess nutrients from ponds and produce oxygen through a process called photosynthesis.

Oxygenating plants grow mainly underwater and, in addition to adding oxygen to the water, they limit the growth of algae by competing with them for nutrients, which keeps your pond clean, clear and healthy.

Some examples of good oxygenating plants include Arrowhead, Water Primrose, Canadian Pondweed and Eelgrass. Fanwort and Water Wisteria are also good oxygenators, but both can be invasive — so plant them judiciously.

But oxygenating plants by themselves isn’t enough to properly aerate your pond, since they play no part in circulating the water — for that you’ll need a combination of surface aerators and bottom-up aerators.

Close up of a water primrose plant.

What are surface aerators?

Surface aerators work by taking the water from below the water’s surface and exposing it to the air. The water droplets collect oxygen from the air, which is mixed into the top layer of your pond water when they fall back in.

Surface aerators — such as fountains, waterfalls and bubbling rocks — help control algae and weeds but they don’t typically affect the oxygen levels at the bottom of your pond, where you need it the most.

So it’s best to combine surface aeration (which adds a natural ambiance to your pond) with a bottom diffused aeration system.

How does bottom diffused aeration work?

Bottom diffused aeration systems lie on the bottom of your pond and release small bubbles of oxygen-rich air into the water — as they rise to the surface, oxygen is transferred from the bubbles to the water, effectively aerating your pond from the bottom to the top.

This is especially beneficial to your pond’s health — by giving the “good” bacteria enough oxygen, you increase their ability to digest the sludge at the bottom of the pond. This reduces the concentration of nutrients in the pond, which further increases the oxygen levels and keeps your pond clear.

By incorporating all three aeration methods you’ll help your pond stay clean, clear and full of happy, healthy fish.

There’s more to a healthy pond than aeration alone…

I’m sure you’re beginning to realize just how delicate a pond’s ecosystem can be. In addition to proper aeration, there are other factors that will help keep your pond water clean and healthy, such as proper filtration.

But if you find this all a bit overwhelming, you’re not alone. In my experience, most people want to be able to enjoy their ponds without needing an advanced science degree!

Healthy aerated backyard pond.

Enjoy your pond without the hassle.

Bottom diffused aeration systems lie on the bottom of your pond and release small bubbles of oxygen-rich People who own cars aren’t expected to be mechanics… so pond owners shouldn’t have to become marine biologists in order to enjoy their backyard ponds.

If you’d like help managing your pond and keeping it healthy, give the team at Raymar Landscapes a call — they’ve all been trained by Aquascape, North America’s leading manufacturer of water gardens, water features and ecosystem ponds.

They’ll take care of all the technical aspects of your pond, leaving you free to watch the fish dart amongst the lily pads while listening to the soothing sounds of the water.