Coco is most definitely HYDRO!!!!
Your pH of your nutrient mix for easiest should be 5.8.
This pH is the basis that should see you through your entire veg and bloom.
Once you get to grips with your nutrients you can start tailoring mixes at certain pH's to help certain elements be uptaken easier. But that's a couple of years away yet.
Also with the CNS17 are you using the grow bloom and ripe?
Which version if the grow is it? There is one with I think NPK of 3-1-2 and another with like 3-2-4.
Alot of folks are just using grow and ripe during flowering.
J