Saturday, August 2, 2008

Water Aeration

In spite of having little rain, the pond basin is holding water very well so far. There has been sufficient time for the clay sediment to separate from the water and sink to the bottom. Accordingly, the water clarity is very good.

However, this raises another issue that I knew in advance I would have to address, and that is aeration. Left untouched by human hands, ponds eventually fill themselves back in. That is nature's way (I have seen ponds created two generation prior left untouched and they are mere hollows in the ground). The obvious exception to this rule is when there is a strong feeder creek, or springs, etc., but even then over more time you will likely end up with a marsh or swamp area.

But in between this terminal end of ponds is an ongoing invasion of natural plant growth. On the one hand, some plant growth in the pond is necessary for establishing a balanced ecosystem. On the other hand, no one builds a pond just to come and look at scum floating in the surface and weeds tangled underneath. Unfortunately, you can smell it also. Anyone who has tried to fish or swim in these conditions knows exactly what I mean.

My plan is to head this off at the pass by introducing a pond aerator. While there are many different designs and ways this system works, the basic idea is to introduce oxygen into the water as well as rotate oxygen-depleted water off the bottom (thermal layer stale water). The short of it is that this keeps a pond fresh, clear, and minimizes nasty scum (algae).

This type of aerator sits on the bottom and injects or bubbles up (images from

Others sit on the top and introduce an air mix downward:

Other systems, often seen as "fountains," pump water from the stale water below and spray it into the air. It lands back into the water introducing oxygen. There are many different nozzles and spray patterns from which to choose, but I like ones that look the most natural. Among various possibilities are:

I will need to do some more investigation as to which aeration system would work best for our size pond, while simultaneously being economical in energy use. In a later post I will also describe my plans to build a rock waterfall, so hopefully I can incorporate one pump to handle both systems. But more on the waterfalls later.


Mark said...

I think I might have an aerator that will incorporate your waterfall and it is shore mounted making it easier to do maintenance on. The system uses micro bubble technology and delivers 100% DO. It also pulls the water from the bottom and reintroduces it at the surface. This will allow you to let it flow over your waterfall while saving energy by not having to force air to the bottom of your pond.

If you would like more info, please e-mail me at

Martin D said...

I know the perfect place to help you with your problem. I had some similar problems over summer and Kenny at Absolute Aquatics helped me out a ton. You can reach him here I hope this can help you out