When I see plants like yours, I immediately think "phosphorous deficiency." The light new growth leaves and red/purple stems -- petioles, but especially red/purple or striped stalks -- are classic signs.
I had the same problem as you do, and they looked the same, even down to the interveinal chlorosis. I'm in Fox Farms Ocean Forest, and I posted about it somewhere around here. Turned out to be phosphorous for me, which is why I'm jumping in here. I disagree with you about FF being hot; indeed, I found FF Ocean Forest to be fairly devoid of nutes after just a couple weeks. That was a surprise, because I thought FF OF would at least take me through veg, which is why I stupidly allowed the deficiency to take hold. Starting a good overall and fairly heavy (for me) feeding regimen fixed it right up.
Disclaimer: I'm no expert. I'm just an old lady raising cannabis in her old age, and I'm still figuring all this shit out. My cannabis plants will talk to me; the hard part is learning how to listen.
