incubators can be very tricky i found , i only use a hova bator but now get very good results through trial and error , i was advised not to put any water in at all untill the eggs start to pip and its worked like a charm , that advice was off somone who has been hatching for years[please try it ]
stan just joined you all
Hi Stan,
Your experience is not untypical of real life situations and if it works for you then actually it's not that unusual. However don't everyone assume that this will work for you when hatching with a different incubator in a different part of the world and in a different environment.
Water needs to be lost from the eggs through the incubation process. A sitting hen will maintain a slightly higher humidity than ambient and that's why incubators are recommended to artificially raise the humidity. However the actual extra humidity you need to provide in any given incubator depends on several factors such as the ambient humidity, whether it has forced air (a fan) as obviously a fan will increase drying and therefore needs higher ambient humidity, the amount of exterior ventillation, too little ventillation will hold in the humidity caused by the drying eggs, the design of the incubation chamber its self for similar reasons. Ventillation is one factor most people don't think about and it's highly relevant. Every time we raise the lid to candle or fiddle about we lose humidity and too much of this I suspect is the reason many people have problems with chicks pipping but not hatching before they dry to the shell. Similarly too little ventillation can cause hatch problems with unhealed tummies and sickly chicks.
A well designed and characterised incubator will have a fan and ventillation system which helps to maintain consistent results between different egg loads. If the designer has done proper characterisation of their product you can rely on their instructions but there's still the external humidity variable which they can't really account for and your own experience can help to optimise. So there will always be a trial and error element.
You can of course take guess work out of the equation completely by having a 'test' egg which you regularly remove and weigh accurately to determine actual moisture loss so you can vary humidity up or down to fit an optimum weight loss curve (data is available for this). The next best method is to measure and control the humidity. Unfortunately accurate instruments to do this are expensive and the cheap ebay ones are highly suspect.
Or, as in most cases, it's not that critical and if you have a good incubator (as described above) you can do as virtually all enthusiasts do and just follow the instructions and learn a few tweeks from your experience.
Happy hatching
HF