guess we will see3.5 ph is acidic as hell youve likely toasted the roots, time will tell .
I also would b careful adding more water as to much water will kill em too espically that youngguess we will see
you from colorados i heard they had a lot of issues with rust spotsusing soil ffof on 5 2 week old seedlings. one is turning hello one got 2 rusty looking spots and one the leafs are very dry and would crack if pinched a bit. after i fixed the PH of my water i rewatered them to try and "flush" the soil. i can take pictures if needed.