Is there a reason you use unchelated? the reason I ask is because most of my Micros are chelated, but I haven't tried other sources. have you done so and have you found any difference?If my journal at TPT was still up I'd just point you to the page where I went over it. I make up a 1000ml solution and dose 20 ml per day so lasts about 50 days. I make the solution with RO water and add 10 ml of distilled white vinegar and 0.4 gm potassium sorbate. The gram scale is a typical jewelers model that goes to 0.01 gram. Shake it like heck every so often for a few days and keep it stored in a dark place. Mine is in a closet and I have never had any issue with mold or anything like that.
For the items that are very small amounts I create a separate 1,000 ml container (Nickel Sulfate Hexahydrate, , Copper Sulfate Pentahydrate, Sodium Molybdate) and add that to the micro 1,000 ml solution. It's a bit more math but not that bad.
The ferrous gluconate is dry.
Once you do it once you will see how easy it is.
Let me know if you have any other questions.