Thank you for your question. The most important things to keep in mind when setting up the cage or aviary for you finches is that they require ample room to fly around and they must be safe and disease free.
Unlike parrot species that climb in their cages, finches get their exercise exclusively from flying. This is why it is imperative to make sure that the cage that you have for them is quite long. They care little about the height of the cage, but the length is all important. For a cage with 9 Finches, the bigger the cage, the better for your birds, to give them more space to fly and you may want to split them up into two large cages. The Large Economy Flight Cage (item # 30740) may be a good choice for your birds. This cage may be found at the below link://www.drsfostersmith.com/produ...