I grow with the red bag of promix from Walmart….. I feed plain water for the first seven days or so, then start nutes at 1/4 strength and increase from there. I feed nutrients every single feed until the end….Not familiar with cx. I used to use the HP, but now it's just plain pro mix from Lowes I'm pretty sure it's peat moss. I have to add my own perlite, but way cheaper than buying HP. Just looked it's peat.