Cockatiels kept for breeding are usually kept either in aviaries for colony breeding, or with breeding pairs in their own individual cages. My personal opinion is that if a bird is to be caged for a large portion, if not the entirety of its life, then that cage should be big enough to allow the birds space and toys to play and fly and keep them entertained, rather than as an extension of the nest box. Very few people have the space or funding necessary to facilitate this, so birds can end up in cramped conditions with little to no stimulation other than their mate. This isn’t what I wanted for my birds and so I only have a small number of pairs, allowing me to give them more space to be themselves as opposed to baby making machines.
My birds live in the house with us. They have a 9 x 3 foot aviary in our conservatory which I like to keep stocked up with ropes, swings, ladders and toys for them to play with, with plans for a larger outdoor aviary too. I do have a large cage which I am using to house the birds that I would like to pair up, based on their genetics, after which they will be put back into the aviary with their friends.
I feed my birds a varied diet, which includes seeds, kaytee exact premium and a mix of various veggies and green-stuff, some of which includes; kale, spinach, lambs leaf, green beans, peas, broccoli and other soft foods and treats for when they have babies. (Egg food on toast is a particular favourite for my birds with chicks in the nest!)