The Bluelab Guardian Monitor provides 24 hour continuous reading for pH, conductivity (EC/ppm 700/TDS/CF) and temperature within a nutrient solution.Optimizing these critical parameters through a plants’ growing phase helps ensure a successful crop.Designed for indoor use, the Guardian Monitor can be mounted on a wall or hung on a support bar. Set up your reservoir, place the pH and conductivity probes in the solution, then adjust and glance! \n Simply set high and low alarm states – if the solution moves away from the ideal range, the display flashes. A quick look at the monitor will let you know when your nutrient solution needs adjusting.Features Plant-safe green LEDs Large easy to read displays No calibration required for conductivity and temperature Simple push button pH calibration Selectable values for conductivity and temperature Flashing high and low alarms Greater tolerance to RF / electronic interference provided Water resistant design International power supply included Replaceable double junction pH probe included Adjustable display brightness Non-volatile memory (setting retained when power lost)