Go ahead and make a relatively small
dry test mixture. Be sure to wear protective gloves and eye wear in case some reaction occurs.
After mixing well, add 1 level teaspoon to 1 gallon of clean water; or about 15.6 cc to 4 liters. Be careful of fumes. Mix, let sit for several hours, and mix again. Check the pH.
The desired pH range is 6 to 6.5. If it is between 5 and 6, then adding small amounts of Calcium Carbonate will raise the pH without significantly altering the nutrient properties.
If the pH is below 5 or above 7 (doubtful) then you'll need to rethink your mixture.
Mycorrhizae (Mikoriza) are fungal spores. They must come in contact with roots within a few hours of mix with water or soils. Application above ground by water or cultivator is not effective. Application to bare roots is the best method.