Beginner grower problems

[90Gizmo]

21 days. I know I overwatered to start but haven't watered since Sunday (4 days ago far.) Spotted leaves have gotten worse, first true leaves are dead. I've misted with Epson salts because it looks like nute deficiency to me though I read that way roots can make it look like that. I started with "organic potting soil" with no added nutes for the seedlings except the plugs they were sprouted in. I added 1/3 of 12-4-8 fertilizer to the water starting the second week. I added worm castings 4 days ago before the last water. Also, that was the first time I adjusted my ph 8.5 water down to 6.5 before watering.

The plant seems to be growing well but dying from the bottom up. I raised the lights a few days ago mostly because I wanted to do something... I'll make better dirt next time but don't know what to do for these

[90Gizmo]

Going though the repair guide ... I think that it looks like PH problems. I'll concentrate on that first.

[Puglover1]

You might need calcium too. You can make egg shell water if you want to do foliar spraying. But yeah, pH matters for nutes to be absorbed. GL

[GuitboxTom]

90Gizmo , good idea to focus on pH. 8.5-6.5 is a large fluctuation. 6.5 is Good. The lower leaves usually get absorbed by the growing plant. New growth looks better.
Be sure that there is microbes in the fertilizer to help with root zone uptake of nutrients.