I have three hives in one of my two apiaries All three hives consist of one 10 frame deep and a ten frame medium. Each deep in filled with brood and honey, but the top medium boxes are not full. One top box has seven frames of brood and honey, one has six frames of brood and honey and one box only has three frames of brood and honey. There was rain a week ago and many blooms have come forth. The bees should have good forage, and my area is still three to five weeks from a frosty morning. If the bees don't fill out the top mediums, should I place an empty super on for the winter? I may want to put a candy board on later in the winter in December or January. Will a medium box without any honey or brood be detrimental to my bees? Can I feed on top of an empty frame?