When does the Dissolved Oxygen level in a waste pond typically reach its lowest point?

The dissolved oxygen level in a waste pond typically reaches its lowest point at sunrise due to a combination of biological and environmental factors. During the night, aquatic plants and algae cease photosynthesis, which means they are not producing oxygen. At the same time, respiration by fish and microorganisms continues, consuming the oxygen that is present in the water. As a result, dissolved oxygen levels decrease overnight and typically reach their nadir just before or around sunrise.

In contrast, during the daylight hours, photosynthesis resumes, and oxygen is produced, leading to higher levels of dissolved oxygen. This phenomenon is particularly pronounced in waste ponds where the biological activity can significantly deplete oxygen levels overnight.