when do i transplant into soil?

Hello I bought fem seeds (Great White Shark) 6 days ago and germinated them.

They are now all around 2 inches tall and have there "true leaves" I have them in rockwool cubes in a humidity dome under 3 energy saving bulbs.

I am wondering when are they ready to go into my grow medium (soil) and under my 600w hps? I also have a 400w and a 250w so if the 600 is too intense then i can use a smaller watt bulb thanks:cheers2:

 

Well would think there gonna out grow ya dome in a week or so lol so maybe then. Never done but if they look strong would say at 4-5inches prick out and pot on.
As for lights the more watts only means more coverage and more cost, try and aim for 30-50 watt per square foot being small your plants won't need more then 250. switch to the 600watt on your next pot up again.