Make sure u soak your rockwool cubes in 5.1 pH solution to break down the lime for 24 hours. Then start off with a 3 liter bottle of poland spring and add 1/2 tsp. each of whatever nutes your using until they sprout. Your best bet would be to soak the seeds for 24 hours, place them in a wet paper towel sprayed with your solution until they sprout a 1/4" to a 1/2" root and place them in the cubes tip down. Apply a low level of light until they come up then you can add a little bit more light but nothing over 40 watts of cfl output for a couple days, then 100 watts to 300 watts of cfl's are fine at the right distances. Just keep watering the cubes when they dry out or even place them in a tray and leave a centimeter of water in the bottom. The rockwool cubes will wick up the right amount of moisture needed.
Hope this helps