Did you rinse the Rockwool before use, with properly ph'd water?
What's the ph of the water you're using?
Are you keeping the Rockwool damp, or have you let it dry out between waterings?
Why are you starting in Rockwoll, then putting them into soil? Why not germinate 'em in a bleach-free paper towel? (cheaper and quite effective)

Some seeds covers are stubborn hard, and may need coaxing to germinate. A gentle scuffing with 180 or 220 sandpaper will allow easier access for the moisture to enter the seed.
Rusty Trichome Reviewed by Rusty Trichome on . Seed Problem from Nirvana Not Sprouting Hey guys so i bought 10 white widow seeds from Nirvana and they arrived very quickly and discrete. I germinated them all in paper towel on a dish covered with saran wrap so humidity would stay high. They all germinated very well within 48-72 hours. I then put them all in rockwool and only 3/10 have signs of any seedlings after 4 days in the rockwool. I have CFL on them and proper ventilation. 1 of the 3 that sprouted the seed is coming up so i know that one will be ok. the others u can just Rating: 5