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 Bluelab� 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! 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. The Bluelab� Guardian Monitor is the simplest and most effective reservoir monitor you could ever own!