I think that the most important thing with hatching duck eggs is the humidity during the hatch. They seem to develop just fine, but if the humidity is too low during lockdown, they just get shrink wrapped in the egg. I learned this lesson the hard way with my first hatch. Most importantly don't open the bator after lockdown. Its so hard keep your hands out of it I know, but if you get the humidity up, the best way to keep it there is to not open the bator. If you have to add water, use a tube. This has really helped my hatches.

