I have grown using just about every method over the years. I've tried all of the popular nutrient lines at least once. I've obsessed with this and that. I've made all of the mistakes and learned along the way. What I have come to realize based off of my experiences is that simpler is better. There is nothing simpler than 100% coco and blumats. I'm on my fourth grow with this method and everything is going great. The first three were some of the best grows I've ever had and they were the easiest ones ever.
Here is my story.
First thing you're going to need is a nutrient. I chose VitaGrow. It works great with coco because it uses calcium nitrate for the nitrogen source so throw that bottle of calmag away you won't need it. It's a three part product and is very inexpensive. The only thing I add to that is fulvic acid during veg and epsom salts in flower. You're going to need a PH pen because PH is extremely important. Screw the PH up and you're going to have issues. I shoot for 6.0 throughout the grow. VitaGrow maintains that PH without any wild swings.
These are the nutrients I use and I use them according to the instructions except for diluting it for new clones and young seedlings. I also start reducing towards the end of flower so that when I harvest I am at 1/4 strength or less.
You'll need a reservoir to hold your nutrient solution. I just use an 18 gallon tote and run the line through one of the bottom vents on the tent. I also have a small pond pump on the bottom to keep the solution moving and aerated.
The plant on the left is a cross I made of Strawberry Kush and Ketama. The tall gal in the middle is a Pakistani Chitral Kush. It was the short one until it decided to stretch. Back right that you can't really see is a Night Nurse and the front right is a Black Domina that went in a week after the rest due to some issues I had following a PH issue from using a bad PH pen. They're all doing extremely well. No spots, blotches, yellowing leaves, curling tips, etc...
It's a set it and forget it method of growing. All you do is keep the reservoir filled. I can buy enough VitaGrow to last a year for what some people pay for one bottle of an additive. Epsom salts are $2.00 a pound. Fulvic acid is extremely inexpensive if you buy a pound of it in water soluble powder form.
That's it.