Pond turnover
During summertime, without proper water circulation, ponds will settle into 3 layers – known as thermal stratification. The top layer (epilimnion) is the warmer water near the surface. The bottom layer (hypolimnion) is the cooler water at the bottom. The layer in between is the metalimnion. Within the metalimnion is a horizontal plane called the thermocline – the point of sudden temperature change. If you have ever jumped into a lake or pond and felt an instant difference in temperature, you passed through the thermocline.
As the temperatures drop, the warmer water at the top of the pond increases in density and sinks to the bottom. Eventually with the addition of windy days, the pond will mix, and the temperature will become more consistent throughout. The biggest concern is a sudden drop in temperature or a major storm that turns the pond over suddenly. If this happens, anoxic (anaerobic) water at the bottom of the pond can mix throughout the water column and deplete oxygen levels. This leads to a reduction of beneficial bacteria and the possibility of a major fish kill.
Read more about fall pond aeration here.
Benefits of aeration in the fall:
Subsurface aeration increases dissolved oxygen levels helping to offset the reduction in oxygen from plants. Aeration allows for beneficial aerobic bacteria to multiply, speeding up the consumption of organic matter that has accumulated in the pond. Subsurface aeration also circulates water to make temperatures and oxygen levels more consistent at all depths – preventing the devastating effects of sudden turnover.
For additional content on pond aeration, please visit our pond page: https://www.hiblow-usa.com/applications-guide/pond-aquaculture/
If you have any questions, please give us a call, or send an email.
Phone: 734-944-5032, Email: info@hiblow-usa.com