Thanks Padawan. I checked out your "head scratch" post and found that helpful. Looking around, me thinks it might be a magnesium problem, but not positive. Anyway, I'm going to checkout the soil pH and maybe add a little Epsom salts or Dolomite lime. The thing is .... the cup has some worm casings and a proper mix of Mephisto SuperSoil in Roots Organics Original, same as the other solo cup which is doing great with the Chem Bubbly, so I really don't think the medium is the problem -- I suspect its more about something finicky with this particular strain. We'll see.