I tried to be nerdy about pH...even bought both a powder kit tester and a weird metal gauge thingy (which seems to be wildly inaccurate). I had read that if the pH is too low, essential soil nutrients can't be absorbed by some plants - in my case I think it was calcium becomes unavailable to zucchini. Turned out my soil was the opposite...seriously alkaline. Acidified it...still no improvement with the zucchini! So I gave up on pH