The HOEI (18.3" x 18.3" x 22") cage is an excellent cage for Brotogeris birds and gives them plenty of room to move around. They are difficult to find these days, but a cage similar to this would work fine for your pet. The cage that you select should have 1/2" to 3/4" bar spacing. One would suggest putting newspaper (cut to the cage size) in the bottom of the cage for adult birds; make a stack of about 10-20 papers high and then just remove the top soiled paper every day as grey cheeks tend to be messy--both their food and stool. However, if your Brotogeris is still a baby, being hand fed, and lives in the bottom of its cage, newspaper would not be a good choice.
It is necessary to give your bird fresh water every day. All food dishes, glass water tubes, etc. should be washed in hot, soapy dish water with a capful of liquid bleach--lemon Clorox is good--added to the water to disinfect the dishes at least twice a week if not daily (also a good idea to clean their wooden perches and all their toys as well in this solution making sure that the perches and toys are rinsed well and dried off before putting them back in the cage). The entire cage should be dismantled and cleaned with the same solution at least once a month. [Also see article How Clean is Clean?]
It is important to provide a variety of different perches for your bird, so that their feet do not get sore from being in the same position all the time. Some suggestions for mixing and matching are: 1/2" wooden dowels (untreated), Comfort perches, small or medium Booda cables, natural manzanita perches, and a small (3/4") cement perch to keep their nails dull.
The site owner suggests that one purchases (or makes one's own) play area for your bird as grey cheeks need a lot of "out" time from their cages when you are home and can supervise. For your bird's safety and to better train your bird, make sure your bird's wings are clipped first by a professional; your bird's nails should be clipped by a professional as well since windows, large mirrors, food cooking on your stove, commodes, etc. can endanger your bird's life). If kept in their cages too much, some grey cheeks can throw temper tantrums that you would not believe! Grey cheeks also need a wide variety of toys to play with to keep them entertained (but don't overstock their cage with toys so that they have no room to maneuver!).
In addition, rotating toys every week or two will help keep them from getting bored. The owner's bird enjoys playing with toys that have bells on them. They especially like rope toys that they can swing and climb on (and hang upside down from!).