Seedlings

When do you transplant? Is it once you get the second sprout of leaves?

Also how can I prevent the seedlings from snapping or falling over? (I bottom feed water) I keep it covered with a humidity dome. I only seem to have the issue of the seedlings falling over and snapping in my seed tray, when I direct sow, I don’t seem to have any issues. Not sure if maybe I need to keep the dome off and get them used to the wind ?

Also tried starting quite a few seeds in my worm farm^ then placing into the ground (this seems to work pretty well so far)