frustrating hatch rate

[gracej]

I am just getting back into chickens. This is my second try. Last incubator full I had a low hatch rate. Many of the chicks were partially or fully developed with no pipping. So I added ventilation. I purchased a digital thermometer I found the mercury thermometers were reading a bit cool.
Now I had 5 out of 7 hatch from one breeders eggs and 0 out of 10 hatch from another. The only thing I can see that might be a problem is I moved eggs to a still air from a forced air to hatch. One time I caught the still air at 102.2 but other than that I am baffled and very frustrated. I have 2 more sets due to hatch today and Fri. Any helpful hints????

All the eggs were mail ordered from ebay. I did not let the eggs set for 24 hours prior to putting them in the incubator could this be the problem?

 

[Egghead_Jr]

102 F in a still air is close to the correct temperature reading at top of eggs, 101,5 F is what most still air users use.

I think your problem is simply that your using shipped eggs. It's such a gamble how your eggs will be handled by the postal system. I've done shipped eggs 3 times with drastic difference in outcomes. First nearly all developed, second time only 1/5 developed with none hatching and last time half developed making it to lock down with half of those hatching. Your mail is either hand delivered or kicked across the country and that's the real difference.

To show the difference, this last hatch where 1/2 developed (7 of 14) and 1/2 again hatched (3) we also had our own eggs in incubator where 17 out of 20 developed with 12 hatching and 2 piping but didn't make it.