Not a pro take my words with a grain of salt but some of your plants leaves have reached the edge of the pot might be time to pot up, I have refrained from checking runoff I’m scared I’ll start chasing it and make it worse lol. You’re using
fox farm soil is it
happy frog or ocean forest? Sorry if you stated it already, I’d continue with plain water I was about 3 weeks from sprout before I added anything at all like I said before, and even then do it extremely light like 1/4 dose and work up. Take some pics of the new growth from the pics you have it’s kinda a side view but new growth looks healthy, lower yellowing might be a result of what damage those leaves already had. I just make sure the water I’m using is ph’d to 6.2-6.5 (personally)
As far as your organic question, just because you are in soil does not automatically mean organic (only use neuts labeled as organic to stay organic) I believe if you are using the
fox farm trio (grow big / big bloom / tiger bloom) those are specifically their organic line and says so in the label I use those 3 plus the
cal-mag and microbe brew gunna finish the rest of my run with just those and try to keep those microbes healthy in the soil.
Again I’m a noob as well on my first grow. So others may correct me lol.