Tomato Plants are not producing....

[T'Mater]

Well when i mean phase, what i ment was, how do i know when to up the strength of my nutes. That's what i was alway's scared about. Do you just start with week 1 and give them 1/4 nutes XXXPPM and then week 2 goin up to the next level?

For the most part i stay'd waaay low i think for too long if that's possible.