The new Pond Keeper has no trouble intuitively grasping the importance of filtration and heating for the garden pond which, after all, effects the environment of the Koi pond in easily seen and understood ways. Often air pumps are assumed to be merely decorative, but Koi pond air pumps serve a vital function within the garden pond, one every bit as important to the cleanliness of the environment and the fishes overall health as filtration and heating.
Oxygenate with Air Pumps
The water within your Koi pond contains the entire oxygen supply for the fish living within it, a supply that is naturally renewed over time. But simply waiting for oxygen exchange between the air and the surface of the Koi pond's water is neither optimal nor reliable, and oxygenation is recommended.
Air pumps force air into the water of the pond in the form of bubbles. Each air bubble contains some oxygen, which is exchanged with the surrounding water. For this reason air stones that release finer bubbles are preferred, as it is the surface area of the bubble at which the oxygen exchange takes place. Numerous fine air bubbles contain a greater overall air-to-surface ratio than the same volume of larger bubbles.
Circulate with Air Pumps
Circulation is another vitally important function of Koi pond air pumps. Aeration should be set up in such a way that it aids filtration by creating a circuit whereby water from one side of the pond is pushed toward the filter intake device. This will greatly increase the efficiency of the Koi pond's filtration system.
The importance of variable pump speeds comes into play here, where it is desirable to turn the pump to a low level while fish are feeding and food floats freely on the surface and to a higher level when waste is noticed in the pond. Such speed increases also create interesting experiences for the fish, which have to vary their swimming to cope with changing currents, thus promoting a healthy level of activity.
Not All Bacteria is Bad
Finally it must be said that fish are not the only Koi pond inhabitants that need oxygen, and that an oxygen rich environment must be maintained to encourage the existence of healthy bacteria. Aerobic bacteria -- bacteria that need oxygen -- are an ally in the breaking down of food and fish waste and promotion of a healthy nitrogen balance. Anaerobic bacteria -- bacteria which thrive without oxygen -- can actually release harmful chemicals into the water and damage the health of fish. Promoting the right sorts of bacteria is perhaps one of the most overlooked, but crucial, roles of Koi pond air pumps.