Trying to identify possible multiple deficiencies

Hey all and thanks for your time. So I’m embarking on a fairly ambitious grow this year with two green houses and a fair amount of plans. I have a lot of experience working alongside someone but this is my first solo run. So far all of my plants look pretty damn healthy and I have grown to be about 4 feet already. I’m starting to notice what I think is nutrient burn, but recognizing some other deficiencies as well. Most of the deficiencies appear on the very bottom of the plant as leaves are yellowing and dying off, but I presume they are not getting any light and maybe it’s normal. Some of the deficiency’s have made it up higher, but overall it seems the bottoms are the issue.The plants are a little overcrowded in the room right now but I’m getting ready to finally go outside soon. I wanted to post up a bunch of pictures and basically get a trained eye to look at them and see anything I can correct. As of now I think I’m going to go in and shave up the bottoms a few inches since They won’t be getting much light anyway. Let me know what you think.

medium-fox farms ocean forest soil, with some added perlite and lime

lights-t5 lights on a 16 hour on schedule right now

I only fed them twice with low doses of earthjuice seablast, which I think might’ve caused the burn since I uppotted with fresh ocean forest soil. I also recently introduced silica, and gave them a small dose of cal mag.