Greatest New Year's gift: Critical Sour

Day 64: Feeding day. I stopped giving them the Big Bud supplement and started feeding them with the Overdrive as recommended. Went with recommended dosage which is 2ml/L. There is 2 weeks of feeding left until the final flush. Day 65: Small problem this morning that looks like calcium deficiency on multiple leaves of the 3 plants. Not worried but I'll keep a close eye on this. I went and bought the Sensi CalMag Xtra still from advanced nutrients and plan on doing a foliar spray as soon as my lights turns off. EDIT: Lights are off, I sprayed only one plant, the worst looking one, just to see if it would do any good. If so, I'll apply the same treatment to the others, if not I'll find another solution. I added 1ml to 500ml and gave her 5 good sprays, enough to simulate the evening dew. I know I shouldn't spray during flower but I need it to act quickly. --- 4 hours later, it seems to have at least stop the spread, will confirm tomorrow. Day 66: So it stopped spreading because the lights were off. It looked worst this morning but only on the plant I sprayed -_- the 2 others seemed fine and recovering. I would normally feed tomorrow but they need it fast so I'll add 2ml/L of CalMag today and then 1ml/L after that on other normal feeding days. Also, I figured why the problem happened. I learned that you need to calibrate your measuring tools once in a while... The pH of my solution was way off down to 5.5 when I thought it was good. So yeah keep your tools clean and calibrated! A bit later after feeding, I was wondering if adding the CalMag was really necessary, since the 3 parts nutrient should already have what the plant needs and now that the pH is set well, it should take it in nicely. I'll monitor that very closely. Perhaps I fucked everything up. Day 67: Everything is kinda fine. The farthest is still the worst looking one with a bunch of brown spot on pretty much all of her top leaves. She's not dead but in bad shape. I know I shouldn't expect them to disappear instantly but it makes it hard to say if the treatment was effective. At least I don't see any signs of toxicity. The others seemed to have stabilized too. Day 68: Video update on the calcium deficiency. Deficiency? Well... turns out it's quite the opposite and I'm actually facing a lockout. I should've known since like I said, the 3 parts nutrient already has what the plant needs, and also the fact that I've never flushed them. Experience they call it... So I flushed them with water pH 6-7 until the runoff was in the same range. FYI the first runoff measurement I took was at 5.5. Next feeding will be on Day 71. I really hope that this is actually the problem and that they can now recover for real. Buds are getting fatter by the day. Day 69: Nice They still seem to get worse day by day :( I don't know what to do. Day 70: Fucking Christ!!! I'm this close of throwing everything away. The farthest one is looking terminally ill and I'm pretty sure I see new spots on the 2 others. WTF is going on!!! The soil is still very moist from the recent flush.