Urgent help! nutrients

I guys u need help fast!!!!

Hi I started my set of 6 girls I have a 600 watt light there avout 21days from seed im using cana a and b bcuz root stimulater and a booster all at half strength I had a battle at first witch I flushed and put in fresh pots since then they lookin helthy untill now im also tryed using a cal mag foliar spray and I have seen tgis what issit can anyone tell some plants have not grown wgile some have light yellow patch on the leaves

This is one plant

It looks very dry and underfertilized

It doesnt seem to be much enjoying the medium its in. What is it planted in ?

Proplus with abit of gold label I tryed individual and now have a lil mix it carbt be underfirtlized as I feed refular all at half strength

It needs food, and if your feeding it regularly then your missing something.

U deffo think this another pic letme no plzz