I have not added any cal mag yet.. my plants seem healthy after a few weeks using.. got some small tip burn at 6 grams per gallon.. backed off to 4 for a few feeds then will bump to 5 to finish them offNone. And I've just sampled bud from one of my plants and I'm very pleased! N is only a problem when people are force feeding plants high levels of nutrients. N doesn't "go away" in an organic grow, plants just use what they need. My max ppm is 750, including 100 ppms of cal/mag, which I may not even need, its just years of habit now to add cal/mag to my RO water. I have recently reduced that to 50 ppms and my plants are as healthy as ever.