What kind of deficiency is this?

Plant going on 2 weeks. Transplanted from 1/3 perlite 2/3 miracle grow seed starting mix into 1/3 perlite 2/3 fox farm ocean mix.
Feeding a light 1/3 dose of grow big and a tiny bit of cal mag.

Plant has gone from green and healthy to lower yellowing of leaves and brown coloration on upper leaves. Manganese issue?

Ph of my water around 6.8 with nutes. Have another plant the same age, different strain that's growing well with the same feed, same soil.

Any ideas?

Could be the ph but 6.8 should work for now. To me they look like the arent getting enough water. Maybe do just water for a couple weeks.