That makes sense.
I just thought by dosing both Micro & Macro on the same day is a waste since iron and phosphate form ferric phosphate which is unsoluble when they are dosed too close together ? Im still new at dry ferts also so dont shoot me ;-)
Iron and phosphate will form iron phosphate, but this really only occurs to any large extent in concentrated solutions.
Given that we are dosing small amounts of fertilizer and they are diluted rather quickly in the aquarium, the chances of iron phosphate forming are lower (still possible, however).
I think the one day where the macro and micronutrients are doubled up is fine.