Once you have a pond, it is important to know the exact acreage, maximum depth, average depth, and water volume. This information becomes useful in calculating the amount of herbicide needed for weed control and the number of fish needed for stocking. The amount of oxygen dissolved in your pond's water is the most important chemical feature. Without oxygen, fish simply suffocate. If oxygen levels drop low, fish become stressed.
Stress can then trigger secondary problems, such as poor growth, poor reproduction and diseases.
So it is vitally important to maintain adequate amounts of oxygen in the water. The amount of oxygen needed depends on the kinds of fish in the pond. When oxygen is less than five ppm, fish may show signs of stress. Fish kills can occur when oxygen is less than three ppm. Oxygen levels below one ppm are catastrophic.