So being new to growing as I am, I would not waste my time trying to test soil PH. I tried all that and found I need to get the very basics down first. Generally soils are 6.1-7.0 from what I have gathered via reading and talking. I also ran across the issue buying PH pens, you can get a bad one right out of the box. I saw it happen with my own eyes, three separate manufacturers, three bad pens, ranging from $20-$100 so, make sure your PH pen is working correctly, that was my worst mistake, trying to feed when I didnt know my Pen went bad.... My PH also would fluctuate and I killed a nice plant and hurt one extremely bad, they were bushy and looking good, only took that one feed too. Also what Nutes are you using?