Trouble with seedlings...?

I am a first time grower.
attempting to plant seeds in rockwool supported by clay pellets.
the seeds germinate then when I plant them they are unsuccessful.
is it possibly the growing medium im using?
any suggestions? I am wondering if its the rockwool.
Im trying to grow a seedling to transplant it to my dwc system.

4 posts were merged into an existing topic: 3/6 seeds didnt’ germinate