Dark and purple spots/areas in late flowering problem

Hello!
There are these dark purple patches keep appearing and progressing in the last few days. I'm trying to google and image search, looking at def/excess charts but cannot identify whats going on exactly...

These spots appear only on the UPPER leaves, bottom is green and healthy as before apart from 2 old big leaves at the very bottom that are turning yellow and drying.

Setup is:
- Coco coir
- Feeding 2 times a day, good runoff, good drainage
Tap ~150ppm, 1.5 ml AN cal-mag extra, 4 ml GHE Micro and 8 ml Bloom per gal. Idk the exact PPM because meter broke but I'm sure it is not above 1000.
PH 5.9-6.0
- Temp 23 C (74F)
- RH ~40%

This is an autoflower plant, week 8, around 3 weeks to go.
I keep running same feeding strength for almost 2 weeks. Is this some P K deficiency or lockout?

How have your temps been at nighttime? Nothing below 60F I assume? It looks much like P deficiency, with the purple blotches appearing, which in your phase of growth isn't an uncommon element to be short on. For the moment being, I would bump up the nutrients a little bit and over the following 2-5 days I'd watch and see if the symptoms begin to spread less and less quickly. Taking pictures daily of your plants can help you to compare them to the previous day and measure symptom progression. It sounds like your grow is in order, let's just hope that all you're needing is an increase in feed.

Logan Burke said:

How have your temps been at nighttime? Nothing below 60F I assume? It looks much like P deficiency, with the purple blotches appearing, which in your phase of growth isn't an uncommon element to be short on. For the moment being, I would bump up the nutrients a little bit and over the following 2-5 days I'd watch and see if the symptoms begin to spread less and less quickly. Taking pictures daily of your plants can help you to compare them to the previous day and measure symptom progression. It sounds like your grow is in order, let's just hope that all you're needing is an increase in feed.

Click to expand...

Thank you!
Temperatures drop just a little bit with lights off.
I will bump bloom a bit and see how it goes.

I'm a noob and had trouble finding pictures with similar problems

It's quite alright, there is such a huge, raw amount of information about cannabis online that finding a picture accurately reflecting your problem can be like taking shots in the dark! One site that has proven a useful bookmark for me is the site Growweedeasy.com . They may not have the answer or an example of every problem, but they do damn well at covering as many bases as they can. Fingers crossed for ya in the mean time!!

I've just harvested a crop and had the same issue in final few weeks of flower. Never did figure out what it was, i think I may of had nute lockout. Still turned out amazing either away