[NorthWestPoultry.co.uk]

hi guys i would like some advise i have just had my 2nd hatch out of my brinsea 190 the 1st time i set it i had 120 eggs in and got 80 out
and the 2nd time i had 130 in and got 50!! out i had alot of chicks in the shell that were just dead with out chipping!!
what causes this how can 50 chicks get out fine and the rest dont i have been running the incubator dry until day 19 were i toped the water right up during the hatch any one got any advise as to why this happens how can you get a good hatch then a bad one and why do some come out and some dont !!
the incubator has been running at 37.5 and is very steady does raise higher or lower temp wise 

[ellisr]

I would advise putting thermometers in at different places and checking for cold spots, I always run my incubator with a little water in at all times and then up the size of the container on day 19.
I was having bad hatches when I started but then put thermometers at egg levels and found that the temperature was too low once adjusted I have had 98/99% hatch from home fertilised eggs and about 85% from bought in.

[shetlandpaul]

whats the humidity. being to dry is a big killer. other than that you may have bought infected eggs. but at a guess its the humidity