Online digital turbidity controllers can be used in conjunction with turbidity sensors to enable real-time monitoring of turbidity values. Turbidity controllers are commonly used in water treatment facilities, aquariums, and other applications where the water needs to be kept clear. The controller typically consists of a sensor that measures the turbidity, a control system that adjusts the treatment process, and a display that shows the current turbidity level and set point. Some controllers also include alarms or reminders to notify the operator of any deviations from the desired level.