Wow looks like the beautiful start of an excellent grow . Your plants look really good to start, I have seen alot worse plants survive and yes maybe the plants have been stressed abit from transplant, but dont worry they should perk up a bit soon.

I really like your grow cab, lovely reflection

Good luck!

{edit} I don't know anything about MG so sorry can't help you. My fert is 6-5-5 and its fine for me.