I've heard about that whole slurry deal, but honestly, that's just too much work for me. Those Accurate PH8 soil probes are supposed to be the best soil pH testers out there according to many folks. It's probably not necessary for the seasoned growers with more experience than me, but I am really big into making sure I have a solid grasp of the factors behind my grow so I can keep on track and quickly diagnose any problems if they pop up instead of guessing or assuming. So much of learning about growing is anecdotal advice and experience, so I try to get a hold of solid numbers when I get the chance. I started with an El Cheapo Chinese pH meter from Amazon and honestly, it did a pretty good job and didn't need to be calibrated often. I've since upgraded to an Apera PH20, which is more mid-range and not as fancy as the Hannahs or Blulabs. I think it's fabulous quality for the money though and it always gives me an accurate reading. I test it often with GH calibration solution.