The Milwaukee Instruments pH Monitor/Controller SMS122 monitors values in your aquarium and allows you to control other equipment when a user selectable point is reached (it also has visual alarm). This meter has two point calibration and a set point range of 5.5-9.6 pH. It includes electrode, 20 mL 7.01 calibration solution, AC adapter and controlled outlets. You may wish to purchase extra pH calibration solution.Product Manual (pdf format in new window)