The hatcher should not be opened during the hatching process. If all recommended incubation procedures have been followed, the chicks may be removed on the 17th or 18th day of incubation.
Still-air incubators If a still-air incubator is used, normal incubating temperature is 38.3°C (101°F) for the first week, 38.8°C (102°F) for the second week and not exceeding 39.5°C (103°F) until hatching is completed. Temperature should be measured at the top of the eggs. Humidity should be less than 70% wet bulb 29.4°–30.5°C (85°–87°F) until the 14th day of incubation; it should then be increased to 70% wet bulb 32.2°C (90°F) until hatch is completed in 17 or 18 days. Maintaining proper humidity in small still-air incubators can be a problem; do not open the incubator more frequently than is needed to turn the eggs, and do not leave it open for long periods of time.
The eggs must be turned by hand at least three, and preferably five, times a day. A pencil mark on the side of each egg may help to ensure proper turning. It may be desirable to move eggs to different locations in the incubator in case the temperature is not uniform throughout. Newly hatched chicks often tend to sprawl in hatching trays. To prevent this, crowd the eggs into a small area or fasten cheesecloth to the bottom of the hatching tray before the chicks begin to hatch.