Something I cant figure out.

Hey guys. I have something happening to my new plant and can't seem to figure out what is the cause. I use biobizz grow 0.2ml/l as they are stil small. RO water. 0.4ml/l silicon plus, 1/4 teaspoon cal mag nitrate and pH to 5.8. Light is far enough away, so it's not light burn, and not heat stress as it's been 27-30deg celsius. Can't be nute burn as there are no burnt tips, only blotches that seem to dry out. I checked over many nute deficiencies online, but none look like this. Checked for bugs/pests, nothing. The plant right next to it seems healthy, even the effected one seems healthy on top, but for how long... Have anyone seen this before?

That pot is quite small. Looks like she may be getting root bound.

Looks like a rapid rooter plug. Time to pot the plant.

Yes, it is a starter plug indeed. Started from seed a few weeks ago. I am planting them over into 30l pots this weekend. Do you really recon its because it's root bound, I know they can show some strange symptoms when they get root bound.

Don't wait until the weekend, pot them up now

It's quite small for a few week old plant. Just to give you an idea, these guys are 2 weeks old today

Ok, Transplanted the ladies, they are looking much happier this morning!! Don't know why the f*#$ I didn't transplant them earlier!!! At least I know now what they look like when they express claustrophobia