Should have waited a few more days to water. A solo cup of dry soil weighs about 150g if you have a small scale.

Not sure what advice to take now. I watered them yesterday. I pulled the sole cup off seedling and it was bone dry. So I watered them. The roots at bottom looked very dry. This is how they look today.

Hello all. Can anyone please help. I've read all the above comments and still puzzled on what this problem is. I last watered 2 day's ago. Soil in solo cups feel and look dry. The biggest 2 are 3 weeks old. The solo cups are 2 weeks old. I still not given any nutrients. Water ph is 6.5 . Leaves are folding downwards. Led is 24inches away from top of plants. Any help would be appreciated