It is no secret that fish and other aquatic organisms require oxygen to survive and grow. Dissolved Oxygen is naturally added to water through diffusion at the surface and through oxygen producing processes like photosynthesis. Very often, these natural oxygen sources fail to keep up with oxygen demand in a pond or lake.
You can prevent low oxygen level related fish kills and lack of growth by adding supplemental aeration. Aeration promotes healthy, growing fish and will also allow for overall greater densities of fish. Diffused air systems, pond aerators, floating fountains, and water circulators can limit the chances of killing fish.
Pond aerators are the most efficient at adding oxygen and are perfect for shallow ponds. If you are just looking to add oxygen for fish, this is the best choice. Aerators are floating pumps that cause a circulation of water from the bottom to the surface. While similar to a floating fountain, they do not produce a fountain display. While operating, most look like a mass of churning water on the surface. Floating aerators are the best units to introduce oxygen. Fish farms make heavy use of floating aerators.
Diffused Air Systems
Diffused air systems are a great choice for deeper ponds. They are like the aeration system in a fish tank. Air diffusing blocks are placed at strategic points on the bottom of a pond. Air is fed to the block via weighted tubing coming from an air compressor placed somewhere near the pond. The air rises to the surface causing water from below to circulate upward. The system assists in both introducing oxygen into the water and breaking the thermal stratification that locks oxygen deprived water at the pond bottom. This system is only valid for ponds deeper than 12 feet.
For an aesthetic display and aeration a Floating Fountain is an acceptable choice as well. Understand that aerators that produce a fountain do not move as much water. The energy required to form the fountain is energy being removed for water movement. Water movement is the key to good aeration. Fountains can create enough circulation to maintain a pond or at least the area around the fountain.
To handle tricky areas Water Circulators are great at creating directional flow and mixing water. They add oxygen by moving oxygenated water from the surface to the bottom and deoxygenated water from the bottom to the surface. This is done by diffusing oxygen from the air. Circulators are pumps either placed on the bottom or suspended from a float that force water flow in a certain direction. Very handy to induce circulation areas such as inlets or shelter portions of the pond that other aeration can’t affect.
Fish in a pond are typically the largest oxygen consumers. This also means they are the most vulnerable to suffering during periods of low oxygen. Using the right combination of aeration products will insure a healthy environment.