I dont know where the question went but I pull a few leaves, ball them up and put them in a garlic press. I dont think a regular ph meter or strips are accurate enough so you need to buy one of these way over priced meters. Horiba LAQUAtwin pH-22 Compact Meter Potable pH Meter'

I also check the sugar content or Brix on a refractometer The higher the brix level the more terps and the less risk of health or buig issues and the buds store better stay green longer etc. 

However before you go down that road ask your self do you really need to and do you really want one more thing to worry about and spend money on. If you grow in soil or if you have a green thumb and grow in hydro you really dont need to do any of that..