Hi Adam,
Well done 
.
Did the first box you took off (the white one) have your feeder in it?
Are you still feeding?
I’d guess that you could take the feeder off and leave them for a couple more weeks in the bottom box and see how they are. If they have increased their numbers so the frames look quite full of bees and are drawn out more, I’d then think about the Flow super. They don’t look ready to me at the moment.
Adam,
Things are looking good but I would let them finish the comb on those frames. I would think the hive will be bursting with bees very soon and then you can put the super on.
John
Looks like you have plenty of developing brood and the comb is coming along fine. The hive will be humming in another week when you check it. When it is at about 80% complete you can add another box. Depending on your winter climate and the need for bee honey you can put on another deep or choose a medium box. Once that box is at about 80% put on the queen excluder and then the flow box with your flow frames. Lightly coat the flow frames with some bee’s wax and spray some syrup on them so as to encourage them to start working on the plastic frames. Good luck. I suggest that you read the forum on flooding before you install your flow frames. The wires that hold them together may need to be tightened to prevent flooding during harvest. Try to avoid an unpleasant experience during harvest.
Hi Adam, looking healthy and coming along nicely there. A little way before adding that Flow super. I wouldn’t add it till your hive is bursting at the seams with bees and something major is coming into flower. I emptied my Flow super last night (love the way I can extract after work without getting my hands dirty). Sydney Red Gums and Jacaranda’s have filled the hives, Brushbox has just come into flower in the last week, there are plenty of these where you are, this will give your bees a kick along.
As for 1 brood box or 2, in Sydney this is a beekeepers choice and not a necessity for the bees. I personally have used both and out of a choice for myself only use single brood boxes. It means you need to perform a little more manipulation and inspect your hives more often which is a good thing, just remember only 1 box to inspect and not 2 plus if you are looking to re-queen then sifting through 8 frames laden with bees is easier than 16 frames laden with bees. Its up to you, bear in mind if you add another brood then you may not get a honey harvest this season.