Drawing on my personal experience over the years, I found that colony breeding in a captive setting was not nearly as productive as it was when Quakers breed in their natural habitat. After experimenting with colony breeding for nearly a year and experiencing a drastic reduction in the number of eggs laid as well as the survival rate, we abandoned this method and returned to my initial and much more productive single pair to a cage method.
I used to provide a 2x2x2 cages for each pair constructed of 18 gauge welded wire (due to their extremely strong chewing ability) suspended from the ceiling with chain. And although I was concerned because these cages are so small, the Quakers seemed to thrive in their close living quarters, as 7 pairs immediately began laying eggs within 4 weeks of being moved to the separate cages. It is important however not to leave the birds in a 2x2x2 cage their entire lives. I used to put them in the smaller cages usually to breed for two to three clutches then remove them and place in a 4 ft x 4 ft cage with out a nestbox for a couple of months at a time. This forced the birds to take a break allowing them to eat better and exercise. When using the 4 ft cages make sure there are several different perches inside ranging from 1/2 inch to 3/4 inch dowels or branches. This encourages your bird to fly around the cage and exercise more often.
I used to hang nest boxes made of 24 gauge metal only because at the time I had a metal shop, on the upper half of each cage and provide them with plenty of straw, twigs and branches with which to construct their nest. I used metal nest boxes because they could be disinfected with a bleach solution and reused from one season to the next. Pairs also do just as well with simple untreated pine shavings as a nesting material in a wooden cockatiel nest box. Most cockatiel nestboxes are 9″-11″-12″ with a 2 and 1/2 inch lift up door at one end. Just put about 3 to 4 inches of pine shavings in the box and gently pat it down a little. In my opinion, the best nest boxes are the type that hang on the outside of the cage. That way you won’t have to put your hands inside of the cage. Like most other birds, Quakers prefer to be left alone during the incubation and nesting periods, and will protest quite loudly if disturbed. We have been known to peek in nest boxes using a flashlight or candling device for a quick look but it is advisable to refrain from handling eggs or hatchlings unless you are prepared to pull them and care for them.
Some Quakers will abandon eggs and or babies or even destroy them if they have been handled by humans, although this is not always the case. An adequate amount of calcium deficiencies in hens will cause them to eat the eggs they have laid (egg shells contain calcium). If this occurs you can remedy the situation by adding a calcium supplement to their water or food, providing a cuttlebone for them to chew on, or providing oyster or egg shells which can be purchased at any pet food store or pet shop.