Which factor does NOT influence the effective treatment of flowing water systems?

The effective treatment of flowing water systems is influenced primarily by factors that directly impact the chemical interactions and biological responses within the water body. Time of day is generally not a significant factor in the actual treatment processes applied to aquatic systems.

Chemical concentration is crucial because different concentrations of treatment products can determine their efficacy in controlling pests, algae, or invasive species. Weather conditions can also play a significant role, as factors like rainfall, temperature, and wind can affect how treatments disperse in the water, as well as water temperature and flow rates. Fish species preference is important as different species may have varying sensitivities to treatments, thus influencing which products can be safely applied without harming desirable fish populations.

In contrast, the time of day largely affects light levels and fish activity rather than the chemical processes or treatments themselves in the flowing water systems. As such, it does not have a direct bearing on the effectiveness of treatment methods used in these aquatic environments.