What position should the vent be in? Open, closed or half and half?

The position of the vent is dependent on the humidity level.

If you have an incubator without a humidity reading, we would advise from day 1 till the final 3 days to leave the vent half open, or closed unless you start to see the condensation or the incubator starts to ‘fog up’. In this case, open the vent as this 'fog' can be an indication your humidity has gone too high or that the room is too cold. If - even with the vent open - the incubator is still ‘fogging up’ or there is condensation, ensure that the incubator is in a room where the temperature is between 18-22°C.

You then want to ensure the vent is closed for the final 3 days. Whilst your chicks hatch, you may notice some fogging and condensation, and this is normal. If, however, you notice excessive amounts, then half open the vent.

If you have an incubator with a humidity display, then it is easier to monitor the humidity level and the position of the vent. Again as guide, keep the vent half open from day 1 till the final 3 days.

If the humidity is reading too high for a prolonged period of time and doesn’t seem to have come down then open the vent. If it won't go high enough, close the vent and again check the location.  A cold room can not only cause condensation but also draw the moisture out of the incubator.

Then for the final 3 days ensure that the vent is closed. During hatching, the humidity will naturally increase as the chicks hatch until they fluff up and dry out. This is fine and completely normal, but again if there are excessive amounts of condensation half open the vent.