First off you have to know the name of it . Then you need to go to the manufactures web site to se how to calibrate it and use it. Find out if it's just EC or if it gives the ppm TOO..As for the solution, keep that sealed up it is a calibration solution and does not get mixed with anything. You put some in a little cup and dip your meter in it. If your meter shows 800 PPM then it is calibrated. then put the solution back and seal it up. This is the deal , you can check you water, you should be using RO or distlled water. If your water is under 200 PPM then it not too bad if over you should be using nuttrients for hard water. You need to know your water level PPM them mix you rnutes for the stage of your plants life. They should add up together water and nutes. Mixs nutes let stand for 5 minute. then check and adjust the ph.