How to Aerate a Big Pond

Big ponds need big air. Most homeowners have a backyard pond no larger than 20 feet long. But some folks live on many acres of land and have big ponds, 50 to 100 feet long and wide. Commercial ponds are in front of malls or restaurants. The big pond needs a different aeration system than the small one. Large scale ponds collect thick muck on the bottoms, an unpleasant odor and rampant algae. The first question that needs answering is how much aeration is used in those big ponds. A 20 foot deep pond might have a fountain at the top that might circulate water down to about 6 feet, but that pump is not circulating water from the bottom to the top. The bottom 10 feet could have no oxygen. No fish could live there. A big pond must be aerated with life-giving oxygen throughout the water and use that oxygen-enriched water to break down debris and starve the algae, resulting in cleaner water and less sludge.

  1. Install a surface aerator. Surface aeration can be anything from an agitator that splashes to an aerating fountain to a decorative fountain.

  2. Install a bottom mounted diffuser with a compressor on the shore. The lines and diffuser rest on the pond bottom.

  3. Install an aeration system in deep ponds of 6 feet or more. Use a subsurface aerator that churns the water from the bottom, bringing it to the top where it can be infused with oxygen. The deeper the pond, the faster the bubbles rise and the more water they circulate. A diffuser takes air and breaks it into fine bubbles. It's not so much the transfer of oxygen into the water from the bubbles as it is the water that these bubbles entrain and bring to the surface.

  4. Build for aeration. If the pond is too be 6 or more feet deep, make arrangements for the bottom diffuser. For each quarter acre use at least 2 diffusers. If the pond is L shaped, put a diffuser at the end of each leg. If there is a shallow end, put the fountain there.


  • If a diffuser is put into an aged pond, it might stir up sludge that has been anaerobic in the bottom for years. That could create pond water problems that could lead to a total clean out and replacement of water.

About the Author

This writer has been at the writing craft for over 50 years from long before computers or even electric typewriters. Now retired from her day job she spends retirement hours writing for online sites.