I swapped out the micro mix made of sulfates to an all chelated micro mix and it is holding stable. That being said, here are my recipes to make concentrates. For the record, I mix 1 gallon of micro mix, then halve that into 1/2 gallon jugs for compact storage.
When mixing reservoirs, I add 3.78ml per gallon of the above solution. To mix metric volumes, divide the grams by 3.78, though I encourage making 4 liters at a time if doing so as the Molybdate quantity is super duper small respectively. This is the perfect base of micro nutrients that was given to me by a more seasoned user on RIU. So far, I am not seeing any issues at all in my plants regarding micro nutrient concerns.
To mix other components, just add the same weight of each component to a half gallon or whole gallon of RO water. FYI, the closer to zero the RO is, the more precise your nutrients will be, though I am finding that a certain degree of deviation to be totally acceptable. That said, my RO is 10-12 TDS, plus my salts likely have been contaminated by humidity to a minor degree. I've not cared enough to bake my salts before weighing, though some choose to. I am content with the deviations.
378.54 grams to make 1 gallon.
189.27 grams to make 1/2 gallon
When doing it this way, the concentration is only 10% of the volume, so therefore when Hydro Buddy tells me I need 0.572 grams of XXX component, I merely shift the decimal over one position and round off the rest as I see fit. With things like PK or sulfur, I tend to round up for bloom, or calcium nitrate for veg. Beyond that, here are the remaining salts I use;
Magnesium Nitrate
Magnesium Sulfate (Epsom Salt)
Monopotassium Phosphate (MKP)
Potassium Silicate
Potassium Phosphate
Calcium Nitrate
That's it. Nothing else is needed. When mixing, I add the silica first, micros second and calcium last. I also use an optional fulvic humic blend greatly reduced from the suggested dose, but to no degree of accuracy as this stuff is difficult to mix into a concentrate. I generally mix it at a 1/4 strength of 189 grams, and still not all of it liquefies. And when dosing it, I further reduce as desired. Any amount of it will assist in plant vigor as well as helping to chelate the calcium in the reservoir.