I live in Sydney and have already harvested all of my frames over a 3 week period, now it looks like they are nearly all full of nectar but not capped enough to harvest. My worry is that if the bees run out of room to store nectar they might swarm. There is one frame that is possibly close enough to harvest but will that be enough room for them to store nectar just having one frame free? Do other people put a second super on? Thanks
If the weather is humid, I have sometimes put a WSP/medium etc super above the Flow super. The extra space can help the bees to dehydrate the honey enough to cap it. I think that @Eva has found this works too.
I had success with putting mediums on top of the Flow supers this season. The cells got topped off and capped very quickly once I did that. Later in the season I harvested a second time & removed the Flows, and put the mediums on top of the brood boxes for the bees to have this winter.