In those systems you could measure averages of water saturation in plants in each tank/division using your plant tensiometers and then use your pumps appropriately. It would just be another sensor in your installation along with those measuring PH, EC, temp, etc.
Or the ones based on the of University of the Virgin Islands model: http://www.uvi.edu/research/agricultural-experiment-station/...
In those systems you could measure averages of water saturation in plants in each tank/division using your plant tensiometers and then use your pumps appropriately. It would just be another sensor in your installation along with those measuring PH, EC, temp, etc.