Yellowing leaves any help much appreciated!

So im on day 40 of veg and 2 of my plants are showing similar symptoms, ones a little worse right now the other seems to be just starting whatever is going on. The first one is og fem clone I had got from a buddy. It did have spider mites so i sprayed with doktor doom and havent seen any signs of them. I trimmed alot off him and hes been recovering well until over night he kinda did a 360. The other is greencrack fem. There in a 4x4 tent under 315cmh. Temps avg around 26-27c 20-21c at night rh 35-40%. Growing in coco with canna nutes I always ph everything staggering between 5.8-6.2. Do i just need to feed them more? Right now im feeding about 1.2 ec or 590ppm (500). Any help is much appreciated. Seems to be really effecting the new growth. I brought them outside for a min so it was more natural light. Peace love and smoke!

id say burnt from the spray, from the lights.

Id trash it and clean up and start over, it might be another 30 days before she is healthy enough to flower, if ever.

You have more then the common spider mite!

I see signs of Russet mites in each plant.

Now then. To get rid of Russet mites... I might spray them with FORBID 4F and a week later AVID.....

Thing is that this pesky family of mites can actually damage the plants gene's....

I might be inclined to say the plant in the first pic is at that point - possibly!

You can treat them or ditch them and clean the shit out of everything you use and start over...

Russet mites (there are a lot of different types of Russet mite too) are the hardest pest besides white flies (you get white flies - MOVE) to get rid of!

ONLY Forbid and Avid work.....NO organic method will cure Russet mites...period!

You HAVE Russet mites!

I am dead on, 100% correct on this.....

Also be careful spraying any type of product on your plant under a CMH light...they may not run quite as hot as regular HID's, but it's still quite intense lighting.