Final answer:
The correct course of action when chlorine levels are too high is to dilute the chlorine concentration to ensure safety and compliance with health regulations.
Step-by-step explanation:
If the chlorine test on the primary tank indicates that the levels are too high, the correct action to take would be to dilute the chlorine concentration. High levels of chlorine can be harmful to both the environment and human health. Managing chlorine levels is crucial in water treatment processes to ensure safety and compliance with health regulations. Adding more chlorine or taking no action would not correct an already high concentration. Therefore, reducing the concentration by dilution is the proper course of action, and it is essential to adjust dosages to avoid recurrence of the issue.