Both plants are young but yet showing defiencies. Yellow cotyledons means "N" is not present or not being delievered to them.
However, You dont need to feed them with nutes because its too early.
Transparent pots are also not a good idea. Roots must stay in dark.
Your seedlings are searching for light.
I'd start with a reasonable amount of water + lights for the seedlings + covering the pots with some material that'll prevent the roots from getting direct light.
Happy growing
In the first pic the cotyledon is yellow because it was damaged, the other one is fine
should i cut the yellow one? In the second pic u are right, both cotyledons are yellowish.
Transparent pots was my only alternative XD i'll put black tape all around just right now
The first picture shows the only seedling that in the earlier days stretched a bit for some light issues, now they are not stretchin anymore
Thank you for your advice, rep +!
EDIT: I think that black tape will cook the plant so i'll put duct tape instead