3 lb bag of usp grade Epsom, ~4-5$ at the local pharmacy or grocery.
9.87% mg
12.98% s
Put 10 grams into a liter jug, fill with ro water.
Apply at 1mL/L to achieve ~10ppm elemental mg and ~13ppm elemental s.
This is something Id like to get into the habit of doing.. Making stock solutions... for better accuracy..
Great post, insightful!