Dying? Maybe? Idk lol Help..

[Subaru2k13]

So these babies are only a couple weeks in the ground. The one on the left is doing great, but the right not so much. They're in the same exact soil, getting the same light, the same watering schedule mostly. It's in a 2*2*4 tent under a 600w grow star cree cob led light. I've kept the temperature between 70-80 and humidity more on the dry side at 30-40%, only because keeping it up has been difficult in this small tent lol. At first I thought it was over watering so I stopped watering it for a few days, poked even more holes in the side of the cup it's in. It did seem to pop back up for a day or so, but now it's back to this. So again thinking I overwatered it, I stopped for a few days. But this time it hasn't gotten any better. I tried watering it again yesterday and it's still not looking good. A second opinion would definitely be great!

Edit: Also wanted to add that I have an inline fan sucking outside air, into the tent. I had it the other way but I found it'd literally suck the moisture out of the tent, so the humidity would drop wicked low. So I switched it around and kinda blocked the incoming vent into the tent so that there's not crazy wind on the plants. But I make sure to keep the room around 65ish(more on the cool side) to help with humidity levels inside the tent.

 

[Homesteader]

Soil looks a little rich and I think the plant agrees. What is it you are using for soil mixture?

 

[Slickrick82]

No seedling 50 -70 rh present root growth temp good 77- 80 light 28 -30 above plants at lights off lowest 72 try keep little warmer only cuz they small still . I got same tent size wit bloomspect 600w in it. For is we gonna need a fan conter so it can maintained that issue we having better

 

[mysticepipedon]

I think you're overwatering.

When there's plenty of water in the soil and you're concerned the plants are getting dry, the roots are rotting.

It also looks like it's low on N, but that could be from the overwatering. N goes off into the atmosphere as N2O when the soil is wet.

 

[Subaru2k13]

The soil isn't anything crazy, it's just some soil I happened to grab from work. But on the other hand, that could be the reason too. I have absolutely zero idea where the soil even came from lol. I just needed soil as my seeds had already germinated at the time and needed to go into the ground. It's also my first grow, so this soil will never be used again. I plan on switching to FF for my next grow and also when/of these plants make it to transplanting time.
But as far as the over watering goes, I have tried my best to write down when I water, I also make sure I check the weight of each cup periodically to see when it's empty. And when I do water my these plants, I'm using a spray bottle instead of just pouring water straight into the soil. My idea was that it'll soak the soil altogether better using a spray bottle. And I make sure to give both plants equal amounts of water. Which confuses me more since my other plant looks healthy but this one doesn't. Just not entirely sure where to go with it. Fearing I over watered again, I skipped watering it until I knew the soil was dry and now the plant looks even worse. Starting to think this grow is a scrap, and contemplating just starting over with better soil. And possibly better seeds as the seeds I have are from a buddy's grow. He basically gave me an entire full sized plants worth of seed infested buds lol. So I have plenty of seeds to mess around with and try to get this process down. I started with 4 germinated seeds and am down to just these two. The other two, one didn't make it out of the ground, the other I tried in a different soil and it popped out and was doing fine then outta nowhere just stopped growing. With this being my first attempt, I do feel I've learned quite a bit already. BUT there's also still quite I bit I still have to learn. I do appreciate the feedback from everyone!