Hey from far away my plant looks quite good. 1st photo.

but inspecting closer I can say:
I have a small nutrient burn and my soil pH goes too low.
So I'm continuously fighting low pH with dolomite watering, here and there.
right now it is end of 9th week:
plant have a trouble with taking all the nutrients as it should, it seem to have too small "pot" "Air-pot 12,5 l".
It is Auto Skywalker Haze (sativa strain)
I'm aiming for big plant:1m high and thick.
now it has 68cm and it is widespread with many tops, so I believe it need nutrients to hold up.
IMO: next time need to use less potient soil, this one was packed with Nitrogen and it doesn't go well with pH
also need bigger air-pot.
What I don't know?
2nd + 3rd photo:

why newly grown sugar leaves got this strange burns and yellow spots
(suspected Calcium and Magnesium deficiency? or Phosphorus?)

Also why I got purple edge on new sugar leaves?
too much light?
I have TS.1000 (60cmx60cm 140cm tent). lamp height 30-40cm from canopy. 100% power. 18/6
I'm worry about foxtailing hope it will not progress this time. looks like there is quite a bit of stress in growth.
need to go up to 12/13 weeks with this auto. some tips? clues ?
thank you for insight.
I planned to keep her up to 12-weeks as this strain description tells me.
I have 60x hand microscope, trichomes still looks like cristal to me.
Most probably I will start clean watering/flushing this week
(week 10th).