Why aeration in the winter is critical to the health of a pond:
When a pond owner buys a linear air pump, it is often in the spring or summer when they are looking to beautify the water and/ or enhance fish growth. Yet the most important season for aeration may be the winter. Sub-surface aeration is essential for cleaning up autumn debris, preventing winter fish kill, and disrupting the formation of ice.
What is happening under the ice?
In autumn as the leaves begin to fall and other matter starts to die off, ponds collect a significant amount of organic material. Aerobic bacteria in the water – fueled by an oxygen rich environment – eat away at the organic matter. As a bi-product, harmful gasses such as methane, hydrogen sulfide, and carbon dioxide are released into the atmosphere. As winter approaches and the pond becomes completely iced over, the gasses are trapped and begin to replace dissolved oxygen. The loss of oxygen slows the digestion of organic matter which can make for a big clean up job in the spring.
If a pond is covered by ice, there is also a possibility of a fish kill. In addition to the reduction in dissolved oxygen from gas displacement, the lack of sunlight reduces the amount of oxygen produced by aquatic plants through photosynthesis. The combination of these two factors could result in your fish floating belly up come springtime.
