Is this transplant shock or neut def

I transplanted my 3 week old seedlings into 3 gallon pots the other day and when i returned the next day i have noticed small brown spots forming between the veins and the leaves look a bit yellow.
This was the first time they recieved any nutes and only at a weak dose 0.4 ec.
Thing is the plant that wasnt tranplanted (germinated in 2 gallon pot) also recieved this solution and seems to be doing great, only the transplanted seedlings are showing symptoms.

some info= coco + perlite using canna cocoa range plus rhiz superthrive ph 5.8-6.0 watered till runoff.

I feel i have 3 options.

1. flush
2. water with stronger feed
3. Leave alone and pray

Any help ??????????

come on guys i really need advice with this

Wow, that happened overnight? Man, I wish I could be of more help to ya, but all I can really say, is that your PH is okay, and that it sounds like a calcium deficiency. Does your fert have calcium in it?