How do you determine whether and how much to feed the bees? I took out the cylinder and looked inside. The top is full of combs and they are also starting to build from the bottom. In the middle it is still empty. The bees have just under 9 kg, which means I probably need to feed them another 10-15 kg. Is that correct? Or do you expect the bees to consume less with this system?
Hi! From my experience the bees need much less food during winter in HIIVE compared to not insulated magazine hives. Depending on the climate where you live the amount can be different of course, meaning if the winter is “long and hard”. Speaking for middle / east Germany the bees were fine with about 10 KG. I would maybe feed them anything around 2KG, but depending on where you are located this might be not even needed.
Building from the bottom doesn’t sound normal. Could it be that a comb broke off the top for some reason? In this case I would recommend to eject the comb from the bottom.
Regards 
Thank you, I have removed the comb from the bottom and fed it with 2kg. Now the bees have reached the middle of the comb. I can’t wait to see how it looks next spring.