Howdy TWO, I agree with alltatup about reading up on the nutrient(s) that You are using. I have been using the GH MaxiGrow and MaxiBloom line (with some of the GH supplements) The GH nutrient schedule shows a mix of the grow and the bloom nutriments at the 12/12 switch, a transition time, if you will, and this has worked well for me.
It is very difficult to give One advice for their grow without knowing the details of the grow setup, so some details of your grow would be helpful.