Hey Dave,

I was taught to use CalMag at 50% of the total ppm all the way through until I reached the max amount of CalMag recommended on the bottle....which I haven't done yet. By the end of flowering I'm probably at about 500ppm of CM...which ends up being about 5-6ml per gallon. I've always measured it in ppms vs mls which, again, was the way I was taught. I have tons of faith in the guy who taught me to grow so I will stick with that. I use the botanicare line btw so don't know if that makes a difference. Also I recently asked the same people about coco issues and found that they recommend you use less CM for coco applications so perhaps the medium you use makes a difference as well.