Don't use 1/4" hardware cloth for the floor, the poop won't fall through and you'll end up with a nasty mess that is difficult to clean and birds who start getting bumble foot. Use 1/2" hardware cloth for the floor. Some places sell it vinyl coated so it's a little nicer on their feet. All of my cages are made with 1/2" hardware cloth for all sides; 2'*3' and maximum adult birds I keep per cage is 6 (1 male and up to 5 females). Most of my breeding groups have 2-4 females though.