Cockatiels are devious. Here's a picture I took last week of Buster and Shodu checking out the nest potential of a LIGHT FIXTURE. I switched the light on while they were sitting on the edge of the shade (not actually down inside with the bulb) and it didn't faze them in the least. I had to put a piece of hardware cloth over the opening to keep them out, and they spent a couple of days trying to figure out how to get past that. They never found a way ha ha ha.

Yes, I just came to the kitchen, counted cockatiels, and there were only 5 of them. I opened the cabinet that was CLOSED (well, not quite tightly I guess), and our hen was sitting inside!

I seriously doubt she would stop laying eggs now. I am locking her for 12 hours overnight in the cage (kind of dark) but I don't keep the cock in the same cage overnight. After 7am birds start making noises indicating they are awake. They are mating, they are checking places for possibility for the nest. She is due for another egg today, so she is locked again after I let her out in the morning so she could eat (and she didn't , maybe just a little bit). The eggs probably get damaged when she drops them from the perch (no visible damage but who knows about internal).

What am I supposed to do? I thought, the more eggs I hide, the more she would lay?

I know absolutely zero about breeding, but when you put the birds to "bed" at night, have you tried covering the cage with a dark cloth, thick enough to block most light? I only mention that because you say that mom's sleeping cage is only kind of dark, which I think would make it hard to control her sleep hours.

thank you. I normally cover with the bed sheet which still allows light to penetrate (but note that I put them to sleep when its naturally dark too). I cover her cage with a fleece throw now (which is thick) but not the entirely cage - I want her to have some air. I also keep a night light on overnight.

A deal is that they naturally awake after certain time, I would say when it gets light outside, after 7am) so I can see then eating, climbing the cage, preening, playing with still the same set up (being covered) and blinds shut.

Well, She didn't lay her egg in the cage, I thought maybe she is done? I let her out. usually she was laying every 48 hours pretty exactly. She made her way to the cabinet and laid her egg inside the bowl with old pumpkin seeds! I use this cabinet all the time and it doesn't get shut all the way. Anyway, I removed her egg and removed to bowl. Now she is trying to sneak in, but I tied the handles so it should make it difficult.

I am finding that I don't want any breeding cockatiels around I would rather have some of my babies as pets and work with them, train them. Some of our babies are so sweet.

It needs to be dark enough to seem like night. If it's just dim inside it can actually make things worse. It's dim inside a nestbox in the daytime, so a dim, covered cage simulates nestbox conditions. A night light is OK, it's natural for wild birds deal with moonlight. But you don't want it to be any brighter than the full moon.

Its dark enough as long as its dark outside, until about 7.30. After this, it will become dim eventually. I can only put the parents to sleep early, at 7.30, but the problem is that often I am not even at home at this time. Today they went to sleep at 9.

The chicks are doing well. They are eating well and gaining weight (they were a bit underweight), and only the pearl girl is begging her father to be fed. He feeds her only. But, if I offer them formula, the three others would eat. Does it mean they are weaned or not? They are funny, they love to play with green veggie stems. Today my daughter left on the table bowl with spinach that she didn't finish, and soon we saw all birds sitting in the side of the bowl playing with spinach. They ended up dropping it all, but it was still funny.
At what age do they normally wean? do parents ever stop after 2 clutches by themselves?

So what is the next strategy? Tomorrow she is due for the next egg.

It sounds like three of the chicks are able to take care of themselves, but they like the formula and are willing to eat it when it's available. I have adult birds who like to eat baby formula off a spoon.

The usual weaning age is 8 to 10 weeks. Some babies need more time than this, and some need a little less.

If she doesn't lay an egg tomorrow then it looks like you've successfully stopped the breeding cycle. If she does lay an egg tomorrow then you have to make a decision on whether to give the nestbox back to her.

what is going to happen if she keeps laying eggs but doesn't get back her eggs and the nestbox? I thought she would lay more and more.