when to move out of propogator into pots?

Hi,

Got 10 low ryder#2 in rockwool cubes in my propogator moved them in the
growroom after 6 cracked and popped them on the floor under a 600w 2 days ago,

jus wondering when to put them in there pots

thanks

I usually put them in pots when the roots are growing through my root cubes and you can see them and you have your first true leaves. I bury them right up to the cotyledon.