Grow #3 RQS Purple Punch + NL Auto

I was GOING to say you were spot on, but taking a look at your diary, although you're hitting them a little heavy with the Acti Vera and the Bio Heaven, neither of these has any NPK in them so it's got to be that your soil is just a little too hot for them. I would do as you plan - just plain water, probably for a week, and see how they do. The only other cause of that would be overwatering - the state of being CONSTANTLY wet - but I think you'd see more drooping than clawing... In any event, make sure you let the soil dry out thoroughly before giving them anything more and do this every time you water/feed. Good luck - and Merry Christmas (if you celebrate that particular holiday!)

Your instincts are spot on .... potassium! Should you add PK? Yes! Your pH is perfect so if there was enough for her, she wouldn't be showing these signs... and it's about now in the growth cycle that plants are REALLY hungry for both potassium and phosphorus ... so get some to her pronto! Good luck!

Ok.... autopsy report here... the actual TIPS of the leaves are really nothing to worry about and are fairly normal in most every grow... shit happens. BUT the more major yellowing and marking of the leaves indicate a deficiency of postassium - so your instinct about it being a PK issue is spot on. The best time to start extra PK is about week 2-3 of flower... this is when the plant is really needing tons of that and it's hard to overdose on those two nutes - so look for a really good PK booster for your next grow. You'll also be amazed at how much fatter your buds will be if you give this to them. I use General Hydroponics KoolBloom liquid (0-10-10) during most of the flowering stage and switch to the KoolBloom dry (2-45-28) for the last two weeks of a grow. You'll want to cut your grow nutes down to about 1/2 of what you'd been giving them during veg (start cutting them down in pre-flower) and all should be well... Have fun in trim jail!