350-450 yes If i was using one part I would go by what greenleaf recommends in the giveaway thread which i believe is 5-6 grams per gallon and then dilute that back to 50-60%(350-450ppm).. This is what MOG has taught me about diluting MC and keeping the balance in check
"Yes and no, as the PPM of the lessor elements gets smaller it will reach a point where it is not significant to the plant. It is the best way for us to mix lower PPM but it can have issues. I found in my last run that 450 PPM is not enough. I think the sweet spot is between 550 - 600 PPM."