Awesome cage/play area! I bet she LOVES it.Well, I guess I'll go first- this is Chili's current set up...
Her cage stands 5 ft tall altogether, but the enclosure part is 28"H x 31"W x 23"D with 3/4" bar spacing (1" should be the max for Galahs). I would consider this size to be the minimum for a galah, but since I'm home pretty much all the time she's not confined to her cage for very long.
She also has her grapewood gym next to it, so she has somewhere else to hang out, and then also has a window perch on the adjacent window.
Inside her cage she has a big fat grapewood perch (which I need to rotate because she's ripped all of the bark off of it and has started making grooves in it with her beak lol) I also weave newspaper through the bars to give her some privacy on her top perch that extends the width of the cage (and it's also something for her to rip up).
She also has a pedi-perch in front of her main food bowl to maintain her little tootsies...and of course her boing since she sleeps on it.
Thanks! I thought that it would help a great deal to see other Galah cages, to get some ideas from them.
Not too much longer now!! 
That's amazing! How did you sanitize it? Where did you find the wood? Did you buy it? I think that this is a great idea.The grape wood gym I made myself, and hubby mounted eye screws in the ceiling joists so it can hang using SS cable. She also has an apple wood one in our bedroom that I made
Hanging gyms work better in our household because my toddler doesn't try to mess with them lol
Yes- she LOVES to shred things...paper, wood, anything that's easily destroyable and makes a huge mess lol
It's huge! What are the dimensions of her cage (in inches)? I will be getting a cage that is 40-48 inches in width, 30-36 inches in depth, and 60-72 inches in height.Here is Flower's cage:
One thing to keep in mind is that they have HUGE wingspans for their size, and many like to flap around and get crazy in their cages. Ideally they should have enough empty space in the cage to spread their wings fully.
Very cute.This is Pinky's new cage that I put together last night...bear in mind he doesn't move around much and he seems to find the smaller bars easier to climb up - he also has started using the bottom level with the wiffle ball on it and LOVES pinecones
It's the same size cage as our gcc but she's uber hyper and active.
If Pinky was a flyer/flapper I would have bought a much wider cage to allow wing span, but because of where his breaks are he can't extend his wings properly anyhow.
I think you have a good idea of what minimum cage size is for them! If the galah seems to have taken a shine to you, maybe that's who is supposed to be your new flock member?? 
