Yellowing spots starting on veins then expanding

[HeadiesHank]

Hey y’all, this is my first indoor grow and I’m starting to get yellowing I can’t identify. Any help at all is appreciated.
I’m about 35 days into veg using 7 gallon pots with FF HF soil. All ive given it is some worm castings and 1/4 cup of stonington blend organic fert 5-2-4. Temps anround 75-80 Rh is 60-70%. Everything was looking great until about a week ago. Yellow spots starting showing up directly on the leaf veins and then the spots get bigger until pretty much whole leaf is yellow. Ive looked through deficiency pics and can’t seem to identify. I’ve noticed a couple fungus gnats but am not sure if that is the issue or if it’s environmental or nute related. This is my only plant with this issue.

 

[extractoilminussixty]

Strange, looks like it’s mainly up top…obviously lighting too close comes to mind, but don’t really see any bleaching (and I’m sure you’ve considered this already!)
So, I’m thinking Nuit deficiency ?
I’ve somewhat had similar issue & I hit the plant with Epsom salts 1 Tbsp gal H20, Unsulphered Molasses 1Tbsp gal H20 & 2-3 drops super thrive
2-3 waterings, also applied more
NPK Nutrient's
Basically until plant improves 5-10 days, everyone been a little bit different for me, unfortunately always the difficult plant!

 

[HeadiesHank]

Strange, looks like it’s mainly up top…obviously lighting too close comes to mind, but don’t really see any bleaching (and I’m sure you’ve considered this already!)
So, I’m thinking Nuit deficiency ?
I’ve somewhat had similar issue & I hit the plant with Epsom salts 1 Tbsp gal H20, Unsulphered Molasses 1Tbsp gal H20 & 2-3 drops super thrive
2-3 waterings, also applied more
NPK Nutrient's
Basically until plant improves 5-10 days, everyone been a little bit different for me, unfortunately always the difficult plant!

Strange, looks like it’s mainly up top…obviously lighting too close comes to mind, but don’t really see any bleaching (and I’m sure you’ve considered this already!)
So, I’m thinking Nuit deficiency ?
I’ve somewhat had similar issue & I hit the plant with Epsom salts 1 Tbsp gal H20, Unsulphered Molasses 1Tbsp gal H20 & 2-3 drops super thrive
2-3 waterings, also applied more
NPK Nutrient's
Basically until plant improves 5-10 days, everyone been a little bit different for me, unfortunately always the difficult plant!

I thought it could be a lighting issue at first, but it’s only happening to this one plant and I’m using a Mars hydro 3x3 with 2024 version fc e 3000 300 watt dimmed to 25% at 24in for early veg. It’s also affecting lower leaves too now. So I started looking at nute deficiencies and couldn’t really find anything that matches. Was hoping I just missed something obvious and it’d be an easy fix but it’s never THAT simple lol. I’m gonna try whatever people suggest and hope it helps and if not just treat this as a learning experience to get better for next round.

 

[RootFarmer]

This might help