Forgot to ask - are you running in hydro or soil or?
Pretty much everyone Ive seen needs CalMag in coco. If you’re running hydro, I doubt you will need an EC above 1.5. This Blue Dream is supposed to be a heavy feeder, but 1.2-1.3 was perfect all through flower. At those levels, you will find the EC and PH is more stable between rez changes.
I monitor EC daily all during the run. If the EC in the rez is climbing between rez changes, your EC is too hi. If its dropping between rez changes, its too low.
From what I have read on other forums, that 1.2-1.5 range seems to be a pretty common “perfect” EC for hydro. Soil and coco are different stories, so I cant help there.