time plants should stay in the solution

[Jason]

Dear Ron, I have used your plans for the 11 plant system, thanks for providing them, although I am a bit confused on the amount of time the plants should stay in and out of the solution. I am planning on growing container tomatoes in my green house the aggregate that I will be using is leca or the puffed clay. I would also appreciate advice on the best seed starting method. Many Thanks, Jason