I have the BRS 2 part pre-portioned kit. Comes with 1 gal pouch of Calcium Chloride, 1 gal pouch of Soda Ash, and 20oz pouch of Magnesium mix. I know the 2 gallon pouches, you would use a gallon of RO/DI water to mix. Would you use 20oz of RO/DI water for the magnesium mix? No instructions with this thing.