i would start with 5-10% of the mix char. and as your soil ages. slowly add more over time. the easiest way to do so, is add char to your compost, then just add the compost to your mix as normal. over time it will increase slowly which is good.
the rock powders, add about 3-4 tablespoons per gallon if making new soil, or just top dress a light sprinkle on established plants.
the rock powders, add about 3-4 tablespoons per gallon if making new soil, or just top dress a light sprinkle on established plants.
