deficiency symptoms

Hmmm... that leaf doesn't look good! The color of the stem says to me she's starving for some nitrogen but I'm unfamiliar with the nutes you're using and so don't know how much nitrogen they're getting. Plants in flower don't need as much nitrogen as they do in their veg state but they DO need SOME! The one biggest problem I can see is the amount of water you're giving them.... the drooping leaves also tells me the same thing - you're underwatering! You want to water enough to get about 20% runoff (and testing the PH of that runoff will tell you what's actually going on around the roots - whether you've got a PH imbalance or not). The runoff should test out between 6.0 and 6.5 ... if it's lower than that, you should do a flush (3x the size of the pot) to get the salts and nutes out of the soil and when you start feeding again, cut your normal dose in half before going back to your full dose. I think you'll find you've got a bit of a lockout going on because you haven't been watering enough to flush old nutrients out as you give them new. If you're measuring ppm, then that reading should be between 1000 and 1100 at this stage.... late flowering, you'll want 1100-1150. Good luck with your grow ... lots of potential there!