Incubating BCM eggs

[Rochelle Day]

Have you fully calibrated your incubators? Both temperature and humidity? What brand and model are they?

My new one is Brinsea Ovation 56. Only been used 3 times so far. I had two cheap styrofoam ones that I've used a hundred times without problems and another one that I can't remember the brand. I haven't calibrated any of them. Don't even know how to do that. This Ovation doesn't have a way to insert an independent hygrometer/thermometer without causing air leak.

What are the odds that all of mine are off as well as both my friends' who have fancy cabinet type incubators?

Now I admit that the majority of my eggs have really hard shells and tough membranes even though I have several varieties of chickens. I removed the oyster shell from the coop thinking maybe that will help. So far not much change.

I just started a new batch. Half dark and half variety light colors. I lowered the humidity to 40 and will keep it there until day 18. Let's see if it makes any difference.

 

[Rochelle Day]

Like how low?

I started a new batch. Set the humidity at 40. Let's see if that makes any difference. I hear about people not supplementing the humidity but how can that even work?

 

[Lemon-Drop]

I started a new batch. Set the humidity at 40. Let's see if that makes any difference. I hear about people not supplementing the humidity but how can that even work?

Some people live in very humid climates, where the outer humidity is enough.

 

[Rochelle Day]

So here's the update: I kept the humidity at 40 until day 18, then raised it to 50. Something made a difference. I had 30 chicks hatch without any sticky membrane problem. Then two got stuck. They were already stuck when I ended lock down to get the 30 chicks out. The sticky membrane was not as bad as previously. I tried to open up their shells, but there was still blood, so they weren't ready yet. To compensate for lost humidity I put a couple damp paper towels around the two that were stuck. Later two more hatched without problem but the two that had been stuck died. I re wet the paper towels and waited a little longer. Two more hatched without problem.
After a couple hours I decided to call it quits and opened up the remaining eggs. All but 2 had fully formed chicks that never pipped. A couple had distended belly that seemed full of liquid, so I think they didn't finish developing. A couple had tightly closed membrane like shrink wrap. A couple more had gooey liquid around the chick.
There was a variety of eggs incubated and a variety hatched, however there were more dark dark eggs that didn't hatch than any other color. I think I'm onto something with the lower humidity. I'm thinking to keep it low the entire 21 days next time and see if that makes a difference. I think I'm going to get a couple different breed roosters and see if that helps.