What went wrong?

[howfunkyisurchicken]

You need to increase the surface area of the water, not the depth. Try trading out your bucket for a couple of long Tupperware containers if you can. Or, place multiple damp sponges or paper towels around the incubator.

 

[junebuggena]

50-60% humidity is a bit too high. I try to keep things between 30 and 45. And you should be candling periodically throughout the incubation and tracking the air cells. If they aren't growing enough, reduce the humidity. If they are growing too fast, raise the humidity.
Your chicks probably drowned from the air cells not being big enough, due to high humidity.

 

[lushland]

50-60% humidity is a bit too high. I try to keep things between 30 and 45. And you should be candling periodically throughout the incubation and tracking the air cells. If they aren't growing enough, reduce the humidity. If they are growing too fast, raise the humidity. 
Your chicks probably drowned from the air cells not being big enough, due to high humidity.

Thank you. That makes sense. I had asked my husband what the humidity was supposed to be because I couldn't remember. He looked it up and said 60%. No idea what he looked at but I should have double checked.

Is there anything I should do for the eggs that are at day 18 with small air cells? What humidity should I aim for with those?

 

[junebuggena]

Keep it at about 40%. Then, when they start to pip, raise the humidity as much as you can. Aim for at least 60% or higher.

 

[lushland]

Keep it at about 40%. Then, when they start to pip, raise the humidity as much as you can. Aim for at least 60% or higher.

This is what I did for the eggs. It seemed to help. The air cells got bigger. Out of 10 eggs, 3 hatched on day 21/22 perfectly fine. Then nothing else happened. No more pips or anything. 3 ended up not fully developed, not sure when they died. But the other 4 seemed completely developed just didn't hatch. Hopefully the next batch is better. It only had too high of humidity for a couple days before we got it figured out.
I did notice that out of the 20 eggs from the 2 batches, all but 1 cream legbar egg hatched. Only 1 marans egg did (but the chick ended up dying later). And 4 welsummers the first time but none the second. Could that be because the cream legbars are so much smaller it was easier for them to maneuver in the egg to hatch but the marans and welsummers were bigger so the small air cells was more of a problem for them?

 

[junebuggena]

Some breeds are more sensitive to humidity fluctuations. Many people have found that Marans are one of those breeds. Too high, or too low and they just don't hatch.