@djclean808, great 🙌🏼, it‘s very intuitive when you get the gist of it. :)
I always start with the total weight of the substance in my fertelizer and multiply it by the percentage I’m using (4ml of 1000 would be 0,4% so times 0,004) you will get grams so you‘ll have to convert to mg wich is 1/1000.
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