The Pentair AquaPC OnPoint is an automatic chemical control system, continuously monitors pH and sanitizer levels to prevent the ups and downs of chemical concentration. Eliminate eye and skin irritation and odor caused by out of balance conditions. This unit is compatible with liquid feed pumps, erosion type chemical feeders and salt chlorine generators with programmable chemical feed cycle on and off times. The controller is simple to operate and offers one-touch calibration. Password protection prevents tampering or accidental program changes. Manual over-ride offers the user an opportunity to shock the pool in the event of or prior to a heavy bather load. The Flow Sensor ensures the chemicals won't feed without system flow, guarding against false readings and equipment damage.