ok you can test the PH in soil or water. your PH needs to be between mid 5's to mid 6's. if your ph is to high or to low your plant will not be able to uptake any nutes. you can feed it all day and the plant just wont be able to soak up any nutes. to test the ph or your water you first have to calibrate your meter. most meters are basically the same, you hold the "calibrate button" for like 30 seconds then dip the meter into the calibration liquid. but it should have instructions on the meter when you get it. once youve got it calibrated you just dip the probe end of the meter into your water. it will tell you the ph of your water and you adjust from there. you cant buy ph up and down or use some "homemade" stuff. the PPM is the amount of of nutes your giving your plants. the higher the number the more nutes your giving. you can test in soil or water by dipping the probe into the water/nute mix your planning on watering your plants with, or you can test the water runoff in soil. you can get a meter that will test the ph and ppm of your water, but the cheap meter i gave a link to in my last post is just a ppm meter. i thought you were looking for the cheapest possible way out. if you are you can get a ph test from walmart or a swimming pool supply store for under 10.00 its not a meter tho.
