Problem with seedling. Probably very simple and common...

Hey everyone, I'm very new to this and learning as I go. I've been growing these seedlings for about 2 weeks now under a 400w LED light. Watering every 2-3 days, no nutes yet. I have the light on for 24 hours a day. Everything has been fine since lately the leaves have been curling and turning brown. I have looked at all of the helpful guides/troubleshooters but I can't seem to pin point the right problem. If anyone could take a quick look at my pics and let me know what they think and how I should aid it I'd much appreciate it.

how big is the pot cuz the soil looks pretty shallow might wanna give it a bigger home and spread out your watering a lil. almost looks like a solo cup

do you have drainage holes?

what kind of soil are they in?

What kind of water do you use?

It's overwatered and the tap root doesn't have much room to grow down. When using the solo cups, fill them up. And I would be using a seed mix, not soil at this time. What kind of soil? Have you added nutrients of any kind? How many drainage holes in the bottom of that cup?

i would agree the roots are probably at the bottom of that cup already

Thanks for the quick replies!
- Yep solo cup. I'll definitely add more soil.
- About 5 drainage holes at the bottom and a few on the sides
- I'm using pro-mix soil and tap water
- No nutrients have been used yet. But I have some 24-8-16 fertilizer that I intend on using.
- I have a few 5 gallon buckets ready to go should I transport them?

You should most likly transplant them make shore to take a chunk of dirt the roots are in you don't want to yank the hole plant out that will put it in shock and more than likly kill it.