i have some plants that are about 2 to 3 inches tall that had roots coming out the bottom of the one inch rockwool. I then placed those into the bigger 6 inch rockwool. they are doing good and im just watering them often. i was wondering when should i throw these into my flood and drain system. At a certain hight?? and also when i throw them in there at what point should i start giving them nutrients? right away? thanks for the responses