In a message dated 08/10/01 05:04:32 GMT Daylight Time, [log in to unmask] writes: << Have you compared them side by side with hives on regular bottom boards to determine the difference in the same apiary the same year? Has anyone on this list? >> I haven't done anything scientific in the way of measurement. I have about a third of my hives on mesh floors open to the ground beneath the stand (apart from when I occasionally slide a tray in for a 24 hour test). They certainly don't appear to hold the colonies back. My heaviest honey crop this (indifferent) year was from a hive on a mesh floor. I was also using small celled foundation in that hive so there is more than one variable. Chris