Leaves going yellow on 5th week of flowering .... is there a problem ?

Hi, my 2 ladies are in the 5th week of flowering and the buds are growing nice BUT have noticed yellow leaves (crispy) on one plant and yellow spots appearing on the other. I don't want to mess with them too much as they have done well so far.

DR Tent
600w Dual spectrum Light (approx. 8inches from taller plant)
5inch extraction fan with Rhino filter
4inch intake fan cool air
9inch oscilating fan
Plant medium is Coco Canna
Feed - Coco Canna A+B (40ml per 10 litres)
Monster Bloom - 0.6gram per 2 litres)
Feed once a day once tray has dried and soil drying.
PH is 6.5 (don't know the ppm as no meter)
Temp day - 30.0c night - 20.0c
Humidity - approx. 25 - 38


Few pics below to show what I mean, any help would be great guys......

Eh.. They're just leaves.

You're growing Bud now. No need to grow leaves... SOME peeps around here like to color their yellow leaves with green sharpie LOL!

Don't worry about it. Keep feeding, Love your Rewards

The leaves are green enough to produce good wieght.

Remember the more green leaves you have at the finish the heavier and stronger the harvest will be.