All life revolves around the availability of Oxygen. In aquatic environments like fish ponds, oxygen is the single most limiting factor for success. All aquatic life forms demand oxygen. From the fish down to the bacteria any body of water has what is called an “oxygen demand”.
Of all the essential elements in water, oxygen is also in the shortest supply.
Ponds and lakes gain oxygen in two ways:
Photosynthesis by algae and plants.
Atmospheric oxygen is transferred into water at the surface of pond.
Photosynthesis may produce sufficient oxygen for very low fish loads but is inconsistent due to the fact that at night algae and plants remove oxygen through the process of respiration. Most of the ponds and lakes we deal with have higher than natural fish loads and lower than natural numbers of plants and require additional oxygen to maintain a clean and healthy environment. Pond shape, size and especially depth greatly influence air pump requirements. The deeper the pond the less air that it will require per surface area. For ponds over 8' deep a rocking piston pump is required due to the pressure required to pump air to depth. Large, relatively shallow ponds require multiple diffusers, while deeper ponds often require just a single diffuser for up to 1/2 acre of surface area.