If you are going to use mediums for brood, what I do if there is too much space with 8 frames I take a 3/8 or 1/2 in board cut the exact size of the side board. tack it too the inside on one side. 3 or 4 small nails that don't go through both pieces, or you could use screws. The bees do draw thicker comb for honey storage than they do for brood. You could leave as is, and take the little extra time to space them evenly all the way across. hope this helps. d2