The easy way to use those 16 ounce dosing bottles, the ones with the little dose chamber at the top, is to put 16 doses of each of the dry ferts in it, then fill it with water, and dose one ounce per dose. You can put all of the macros in one bottle and the trace mix plus chelated iron in the other bottle. (This is how I do it.)
The problem is when you have a big tank, that takes large doses of each fertilizer. Sixteen of those doses may not dissolve in 16 ounces of water. If that happens, just put 8 doses in the bottles, and dose 2 ounces per dose.