Need help with seedlings showing various signs.

Hey, I’m looking for some help with my seedlings showing some weird signs. Mainly the right two are being kind of funky. I think I may have gave them too much nutrients and I may have gone too long without watering them for a couple days. The little one felt a little dry so I thought I may have too low humidity and turned off the exhaust and misted water to increase humidity. Now it looks as if rust is growing on the slightly bigger seedling. The other two seem to be doing just fine, they are all the same age. Just looking for anyone’s opinion on what I should do to pull these guys out of their situation they are very stunted and haven’t been growing much.

they look like they could use phed water nothing else

I have been doing that for the past couple waters and the one small guy hasn’t grown at all in the past week.

Soil mix?

Fox farms soil.

feed at a higher ph im pretty sure that your soil is acidic their known to be very acidic

I’ve been watering at around 6.7 ph, should I go above 7?