Kind of a step backwards using Rockworry cubes??? Stick with the Coco. whats the issue, looking for simple. Coco in small pot 6" veg for 4 weeks transplant to 3 gal pot done?? If you got to use them than, Ebb & Flow is the way to go, but there are better ways to grow don't you know, check out some other grows then you will know the answer to the question you pose.
Peace