Sick plant need help diagnosing please!

I'm gonna get right to it, she's worsening by the hour and I need solutions. 7 gal smart pot with 60/40 coco/perlite on a nutrient schedule of feed feed water with advanced nutrients Sensi coco pH perfect a and b right now around 600 ppms plus 200 ppms of magical. We last gave it straight water with 10% runoff. Hoping to switch to flower this weekend. But beginning to notice the new growth becoming pale and then yellow. They are also burnt on the ends in certain places in the new growth. The very last picture is from Monday

 

Also the stems are becoming very purple.