So I should add a A and B if I’m using that coco?
No. You need to decide if you want to use that Coco A and B stuff or the GH stuff.
You don't need to use their nutes just because you're using their coco.
If it was me I would forget about the Coco A and B, and just get the 4 GH products and Epsom salt. But I've already got that stuff for an experiment sometime.
I would use the GH because it's easy for me to get help from a master on here that's been successful with it for years. And if NASA and shit uses it, it's good enough for me.
I would listen to what Doug is saying.