First grow and this one plant look terrible please help

[Dbakes420]

So I started some plants from seed and everything was going good then one day this. So I am using pro mix with perlite 20% to volume of worm castings and it was either 3 or 4 tbls per gallon of medium of 4-4-4 gaia green ph is kinda high but can't get an accurate read atm waiting for a ph stick vs the strips I have now