@ISHDoctor, Hi ! and thank you interest
unfortunately, I don't have an answer for your question, only hypotheses.
I live in a region with a limestone soil, so i guess I have more Cal in tap water than other place, but I really don't know about Mg concentration here.
I don't follow the H&G feeding chart, i divide the dose by 3, so I think Cal proportion is good compare to other nutrient.
I was using Hesi nutrient when I start growing, and didnt' experience any Cal Mag issues neither, so I really think it's due to the water from my region. ( South of France )
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