I do not let mine hatch in the nest if I can keep from it. When I see one externally pipped or anywhere else in the hatching process, I move all eggs inside to the incubator. Then they stay in my brooder under a lamp until they are feathered out and I move them back to the aviary. I'm assuming that you are asking when they are old enough to swim? They need a week or two in my opinion, then slowly they may be introduced and under supervision.I don't keep the birds at home, they are on a small plot about 5 minutes drive. Do you let them hatch and remove them before they leave the nest after a day or 2? How long do you keep them under a heat source in the brooder and when do you introduce water? I'm in Ireland so its colder here than Louisiana I'd imagine. When do you introduce them back into the aviary or do they never go back?