Hi buddy, I can see that you are facing over watering in that big pot and you gonna have same problem in other one which is in same big pot.
your watering schedule is not good and plants are being fed with lots of water. You need stop watering until your soil on top get dry and you feel that your pot is not heavy. Then only feed 1 litre to each plant in big pot , let them dry for 2 days then again 1 litre, let them dry for 3 days then 1 litre until you tackle this problem. When your plants will grow a bit, then you can go back to your normal feeding program.
It is better you change your light height to 100-120 cm.