Thank you for your replies, Dude. I usually religiously pH whatever goes in the pot, but I've used the pH perfect stuff before and not had any problems, so I thought I'd be lazy lol. It's bitten me in the backside this round, so I'm back to pHing everything again. I'm using some additives besides the base nutes, so they may be causing the problems, but the other 3 ladies seem to be fine and were fine before without pH checks. It's a bit of a head scratcher lol.
The sick plant is still very sick and she's getting crispy from calcium def. I'm going to flush her again and see if I can get her across the line.
Have you tried Herbies Auto Seed Bank? I used Gorilla, Rhino and Seedsman before, but I have had the best service overall from Herbie. I think they post internationally too, and they carry plenty of Fastbuds so I really like them.
Thanks for all your input, Ripped. I appreciate it.