I am in my first season of harvesting with my flow hive 2 (Brisbane, AU). Due to the great flow and healthy hive, I have harvested from each frame twice over the past few months, usually taking from 1 or 2 frames at a time. I prefer to inspect the super before I harvest, although have only done so twice. Each time after inspection I have given the bees at least a few hours to a day after inspection to calm down before I rob them (otherwise they make it more difficult). I have found though, after each inspection, I only got 1.7 - 2 kg of honey from frames that I have seen are fully capped only hours/a day earlier. I am wondering if the inspection (with as little smoke as is necessary with my hive) is causing bees to uncap and consume the honey. Frames that look capped from the end usually have a great, gaping arc in the centre, so I really do prefer to check. I am interested in your thoughts with this one and what you do before harvesting. I have a refractometer to measure water content, so I don’t have to inspect. I should note the largest harvest I have got from one frame is just 2.3kg… I was so hoping they’d cap it fuller the second time around! I’m feeling a bit perplexed on this and interested in your experiences. Thanks!
Hi @JJJ, I have the same issue of the arc (usually on the centre frames). From what I can work out the bees leave the ark empty for the queen to lay in especially when there is a good flow on in early spring. I find that as the season moves on and the queen’s laying drops off they tend to fill the arc. The honey that is on these frames is generally ripe (if capped) as the cells in the arc are normally completely empty. Be careful harvesting these frames with no capping down low they have the potential to leak into the brood box. Only open in small increments! A full frame with no arc should be yielding about 3kg, if you are getting significantly less than this you could be getting leakage into the brood box. Another possibility is that you have candied honey or very thick honey that isn’t draining. Bees won’t uncap and eat in that short period.
I doubt very much that your inspection is making them move that much honey within a few hours, so I have a few questions for you.
- How long do you take over the harvest?
- What time of day are you harvesting?
I have found that some honey flows very slowly. Patience is needed for harvesting. The first 1-2kg may drain over about 2 hours, and the flow slows to a trickle. But if I wait and leave the frame draining for another 4 hours, I will often get a further 0.5 to 1.5kg. It seems to flow faster if I walk away and do something else… 
Time of day is important. Warm honey flows faster, and while the hive heats the brood nest, they do not deliberately heat the honey super. My preference is to start the harvest at around 10:30 to 11am, so that the honey is draining during the warmest part of the day. I can then wrap things up by 5pm if the flow is very slow.
One other thing. You could inspect the Flow frames after the harvest too. Scrape off some of the cappings and see how much honey is left in the frames. Then you will know if waiting longer might help. 
Just a couple of thoughts for you.
Interesting to read,
In regards to an arc of uncapped cells on the centre of the Flow Frames, it is common behaviour for bees to fill from the centre outwards, but they will feed from the centre outwards also.
Generally, this is more a moving of honey that is above to be down below closer to the brood maintaining the same arc of honey around the brood comb.
If you are finding there is lesser amount, it would be good to troubleshoot and determine exactly where this is. Harvesting in quarters is a useful method. You can harvest a Flow Frame a quarter at a time, monitoring just how much honey is drained, if there does not seem to be a great deal in comparison to a earlier quarter of the same Flow Frame, you could try closing and opening it a few more time, to help agitate the honey and see if this has it flowing more steadily.
It also provides you with an opportunity to inspect the Flow Frame, having been partially harvested to see if honey still remains in the cells, in the case of crystallisation, or perhaps see if the Flow Frame is not as full as you first thought in the unharvested portion.
It also minimises any risk of leaking due to uncapped cells. Giving you an opportunity to inspect if leaking is noticed and draw comparisons again between harvested and unharvested portions of the same Flow Frame.
After an inspection, bees can take a couple of days to settle, and if they feel threatened, they might take precautions restoring honey in available space in the brood box, or maybe even in there honey stomachs.
It would be better to inspect, only the Flow Frames, and do so minimising your disturbance to the hive, often you can get a good look in between the Flow Frames without removing them. Harvesting after doing so, so long as your bees are not excessively agitated from the process, in which case it could be a trait you have to deal with in your colony. Covers for your tubes and jars might be useful. A simple option is some tin foil bent to shape around the tube and over the container. It can be stored and reused quite easily too. –Kieran