Help plants are dying. Have been using LED lightin...

Most likely either root rot or the new soil had too many nutes in it and burned the roots

So when you replanted, it went into the exact same setup? Nothing changed? Yea back off watering if the soil is wet, and if youve got some cfl lights pop them in and they only have to be like 2-3in from the plant if you have a fan. Just double check you've got adequate lights and that their the correct distance. You can water with a Fox farm product called boomerang and its supposed to help with accidental abuse etc, but if you've been waterinh excessively then maybe try to wait a little bit. I'm sorry about the unpleasant turn, but maybe she can come back to you.

Judging from your last pictures, there's not much you can do, they seem 100% dead :( Sorry ... Your soil looks very wet, what's your substratum in the pots? How often did you water them? Did you let them dry between waterings? We need an entire description of you feeding+watering+drying schedule, with nutrients involved and any details you can provide, so we can help you improve your next session.

Hi, Not much stats to go off but looks like your roots have been starved. You should of seen this problem happening much sooner and addressed the issue/ asked for help. The only thing you can do now is give her EXTRA tlc and pay very close attention to her. Don't give it anymore water as you're better off underwatering rather than over. Make sure you have enough holes in the bottom of your pot to allow sufficient drainage as it looks like a DIY pot. hope this helps.

So I'm going to be honest, they don't look good. Led isn't your problem, I use led. But like above has been stated, over watering could be the issues. We need more to work on, Like the following days before she looked like this; Maybe if you had photos of them before it could help. My honest advice, maybe start over, if you can. If you can't, I don't know what I'd do in this stage. How many weeks of veg? If you can give a bit more information I'd be glad to try to help more

Well you give us very little to work with. Nothing wrong with using LED's, I do. I'm of two minds here: First, you are victim of the most common form of rookie mistake: Overwatering, this is by far the most common problem, if you water too much and / or too often, roots can't take oxygen and the plant drowns. And symptoms are very similar to under watering. Also, If the plant is in too big of a container, you will most likely water them too much, resulting in over watering. Let the pot dry, and I mean really dry out before watering again. A plant that size could be given half a liter and last a whole week, if not more before needing water again. Second: When you replanted them, you gave them a serious transplant shock. That means that you damaged the root system. They usually can take up to a week to recover from this, while the re establish their roots Either way, just leave them alone