Large air cells

[DucksAreBest]

Some shells are too poroous and will lose too much moisture. Nothing much you can do about it. It probably will cause problems come hatch time but as has been said, monitor the majority of the eggs, if a couple have porous shells then they might not make it but again nothing much you can do apart from hope for the best.
Maybe your candler is very bright but the shell looks very transparent and thin on the pictures.

Thanks for all that info. I candled the eggs with several different lights and the air cells look the same.

 

[WVduckchick]

Some shells are too poroous and will lose too much moisture. Nothing much you can do about it. It probably will cause problems come hatch time but as has been said, monitor the majority of the eggs, if a couple have porous shells then they might not make it but again nothing much you can do apart from hope for the best.
Maybe your candler is very bright but the shell looks very transparent and thin on the pictures.

Normal looking shells for duck eggs.

 

[DucksAreBest]

Hello, @JaeG and @WVduckchick, one of the eggs with the large air cell died but the other one is looking good.
Here is the dead one:

You can see a little bit of blood ring here:

Here is the other egg: