i don't know where the fault lies, my plant i...

What I would do, if this was my grow, is to flush the plant thoroughly... a good flush is running 3x the pot size of water through so in your case, that would be 15 gallons for each pot. You should check the pH of your runoff and if it hasn't come down by the last of those 15 gallons, run some more through - run as much as you need to to get the pH where you want it (and, at this stage of growth, I'd be aiming for 6.2). Your EC is also pretty high - but it's the pH that's causing the havoc here. After your flush, let them dry out and when you resume your nutes, use only 1/2 strength for the first feeding... The other major problem is your choice of nutes. I would ditch the all-purpose and find something other than the bloom buster you've got going. You need nutes with an NPK ratio of 1-2-3 in flower... in other words, little nitrogen and more potassium and phosphorous... and your EC probably shouldn't be above 1.4 unless you see the plant needing more food. Latch on to some cannabis-specific nutes... BioBizz is organic and compounded especially for cannabis... and there are others. I've not used them but lots of folks have with good results. I prefer the General Hydroponics Flora Series which can also be used successfully in soil grows. Good luck! Get that pH down!!