my starter DWC homemade tub some urgent help plz!!

my starter DWC homemade some help plz!!
hi guys so after a little delay i got the first pot up and running this is gonne be my mother plant tub and my starter my first 2 plants. they are currently in soil.

The plant to the right is from fem seed and its either blue cheese or skunk#1 ill know when the leaves develop more its going to be my mother( if possible) the one on right is orange bud clone i got from a friend.

its ok to transfer my seedling from soil to the tub what should i use isnt it?

my tub takes 6 litre's of water. things i also need to find out are:
can i use some biobizz grow and bloom i used for my last soil grow?
if so how much do i put into 6 litre's?
and If i cant wat do u guys recomend?? this is my first bubbler for motherplant & then clone +first 2 weeks. i need ur advice many thanks in advance.