I'm waiting on neema oil but I'm not sure that's the problem. It's a brand new tent and brand new soil. But I'm new so I have no idea. I raised the lights a little. I water once every 2 days or when the soil is dry. Not using nutrients in the water. I don't have a PH thing here.
Root bound in that mesh, I always take that sucker off..
pH is big and most of the problems..
add a little nitrogen in there.
Could be anyone of those issues. Good luck