A garden pond can be an attractive addition to any property when properly maintained. However, a pond that lacks needed maintenance is unattractive and harmful to its inhabitants. There are a few indicators that a pond is not healthy and lacks sufficient aeration or aeration is non-existent. Aeration or aerification refers to the method by which oxygen is mixed or circulated through a liquid or substance.
The easiest way to test a pond’s aeration is to take the temperature of the water at a depth of 1 foot below the water surface. A difference of 3 degrees of more indicates the pond is insufficiently aerated, a situation where the upper section of water is warmer than the lower section, thus the upper section has oxygen and the lower area is devoid of oxygen but nutrient rich. A key sign is that the fish will congregate at the water’s surface, indicating a lack of aeration.
In pond’s that are under aerated, the temperature difference is still present, just a lower depth. This can still pose problems, since the pond’s aeration system is moving the cooler, nutrient-rich water to the surface, allowing the growth of algae. In addition, since the cooler water is oxygen free it increases the occurrence of “turn over” or reversal of the water sections, resulting in the death of the pond fish.
From these examples, one can see that living water aeration is essential to a healthy, viable pond. A pond’s water must be aerated or exposed to air so that it’s oxygen can be dissolved into the water. The next course of action is determining what type of aeration system to incorporate, either surface (floating) or subsurface aeration. Other factors in deciding on an aeration system include the pond’s size or surface area, depth, and shape.
Surface or floating aerators are often in the form of a fountain providing an aesthetic feature in addition to a functional one. They lend themselves well to shallow ponds and offer multiple patterns to choose from based on the pond’s size and the owner’s personal preference.
Submersed or subsurface aeration systems consist of air stations located at the bottom of the pond that release air directly into the water. Submersed aeration systems can be viewed as a type of underwater fountain that releases air instead of water. The smaller the air bubbles the higher the concentration of oxygen that gets transferred.