Issue with leaves diagnosis?

Hello,

I have a couple smaller plants in veg and they are recently having an issue with their leaves.

They are in coco and are being fed 1.4ec of canna coco and a little cal mag.

The temps are 24-26 C and humidity is above 60% atm.

I feel like I've seen this a long time ago but I can't remember does any body recognise this?

Any help would be appreciated!

What is your feeding schedule?

Once a day so far they are in very small pots and it's not drying out as they are young. Get alot of run off also.