Hi there, just make sure to give them proper pH water around pH 6.5 before you correcting anything.The problem may be because you are not giving her proper pH water or problem in your potting mix.Good luck.
Your main problem is to much water..if your diary is correct you give 0.6l/day since the start of week 2 in a large pot
The problem with watering often is that you suffocate your root system
You can change to different nutrients but the outcome will stay the same
Let your pots dry out a for a few days before you water again and feel the difference in weight and wait with watering again if your pot light again
This way you get a nice dry/wet cycle and oxygen can get to the roots
Happy growing and stay safe
✌️🌱
No plant food is needed at this stage, just water, light, soil, airflow.
400w hps is suggested to be hung 30-36" from seedlings.
What is the temp at the leaves? What type of water are you using?