After my babies bounced back from root bound, dark(and shinier) spots shows this morning, along with purple stem and leaf tips appear burnt. Done a lot of research, looks like phosphorus deficiency, but the dark spots are not start from bottom, it’s on fan leaves only.
Feel free to correct my grammar too, i’m learning English HARD:nerd_face:
Strain; OG Kush
PH of runoff :6.2-6.8
Nutrient？ Advanced nutrients PH PERFECT
Indoor or Outdoor - indoor
Light system, size -LED 280W
Here are some pics form just one day after what you saw above, looks really bad.
The third pic is my most healthy baby, so we can tell the purple stem is definitely something wrong.
After another 9 hours under the light, leaves are getting crispy, touch-to-dust crispy.