Leaves showing scratched marks, deficiency? (Pics in)

hello all!
My girl is an autoflower on day 30 since germination.
It is growing like a beast and trained to have more shots exposed to light.
However i m recently noticing scratched marks on the sides of leaves.
I m using r/o water and giving cal mg at 1/4 strength, , could that be a reason?

Any suggestions/comments welcomed and have a great stoned day!

I m talking about the white stirps in red circles

Other than this it is growing like a beast for day 30 from seed.