When must the low-level alarm on the holding tank be set?

The low-level alarm on the holding tank must be set to "always" monitor the water level effectively. Having the alarm active at all times ensures that any drop in water level is promptly detected, allowing for immediate action to be taken to prevent potential issues such as pump damage or water supply interruptions. It is critical in maintaining the system's operational integrity and safety, as it provides constant oversight of the tank's status. This continuous monitoring helps facilitate timely responses to low-level conditions, integral for ongoing processes that rely on consistent water availability.

Setting the low-level alarm only during specific events, like testing or when the tank is full, could lead to lapses in monitoring that might compromise system performance or safety. Thus, maintaining continual vigilance with the low-level alarm is essential in water treatment operations.