full term embryos dying

[uktech]

are they big? so will they fit in a small incubator

If it helps, here it is next to a nandos card, which is the same size as a regular credit card.

 

[MaryZoe]

I wonder if something else is going on. Her humidity levels worked great for years. Why would that change now? I too have Brinsea Minis and Maxis. I use one well during hatch and fill both at lockdown. I have never drowned my chicks. I have great hatch rates. I might do a thorough cleansing of the inc’y. Maybe it’s a bacteria build up? Maybe your hens are fighting something now that affected the embryos?
I also agree that an additional temperature and humidity check makes sense. I’ve had Brinseas become unreliable after a couple years. You may have to factory reset them. There are instructions how to do that online.

 

[Uff Da]

My hatch rates improved when I started washing/sanitizing my hands every single time before touching the eggs, no matter how briefly. And sanitizing every nook and cranny of the incubator with rubbing alcohol or a bleach solution before each hatch. You can also get bacteria buildup in the humidity channels, so either use distilled or otherwise purified water, and put a pre-1983 penny in the cup--the high copper content inhibits bacterial growth.