I'm going to add medium boxes to my hives. Where should I place them, at the bottom or the top? Is it personal preference?
you are going.....
What you have now there?
How many frames are covered with bees
how many brood frames
how many food frames.
If you have one brood box, another brood box is better that super.
Second brood box is good put down if you do not know when to do it.
When lower box is half full, then swap boxes.
After a week from that add third box above brood =medium.