First you soak the Rockwool (if you insist on using it) in Ph adjusted RO water to 5.5 for 24 hours before you need it.

While you are soaking the Rockwool you germinate the seeds using the Paper Towel method. No superthrive or nutrients, just RO Ph adjusted water.

Once the seed is showing a taproot, place it into the grow medium. Place the grow medium under the light, not in the window. Use the 125w light 24/7 and keep the temperature no higher then 85f and place a humidity dome over the seedling. When the seedling reaches for the light and you see the first set of true leaves you can remove the humidity dome. Watch the temperature now, you need to get it below 80 and add a gentle air movement.

No nutrients should be given to the seedling at all. (Only very experienced growers feed nutrients to seedlings, and most of them still don't do it and play it safe).

Once you see roots sticking out from the bottom of the Rockwool you should have 3 or 4 sets of true leaves. You can now move your seedling into its grow pot and start with 1/4 strength nutrients the first week. Bump them up to normal after that. If you are going to use Miracle Grow soil (not advised) you don't feed any nutrients at all.

That should get you started and on your way.