Is it at all possible that maybe you hadn't added enough KS to your original mix?? I ran into an almost identical problem with my 2nd KS grow of Dinafem Sour Diesel.. Plant was about 4 solid weeks from harvest (based off my estimates), and it just started throwing all sorts of deficiencies.. Checked soil pH and I was good, so I supplemented it with a top dressing of a locally made organic fert that was heavy in the P dept. as that was my worst deficiency.. After a week and a half of attacking it with that, teas and microbe treatments, the plant leveled off but never finished strong.. I had only put about 2.5-3lbs of soil in a 5gal pot and in retrospect, I kinda wished I had either top-dressed it w/ more KS a couple weeks into bloom, OR, just used the whole 5lbs bag in the 5gal bucket (which I'm trying now w/ some seeds), to see if I have the same issue.. Keep in mind, the SD only ran about 70 days on the nose, and I wished it could've gone about 3 weeks longer, but it didn't have too many leaves left.. The smoke was good though..