Question about these eggs I have.

[brettg117]

Ok so I found these 5 eggs aroung the pond that I live near. They are all from my one duck except one. I found them on different days. I found the first one, which is not from my duck Saturday. I found another that was from my duck on Saturday as well. I found two from my duck on Sunday, none on Monday and one yesterday. I have been incubating them in a homemade incubator. I have been careful with the humidity and temperature. Since they are all on different schedules, I have some on day 4 of incubation, some on day 3, and one on day 1. The two that are on day 4 have clear germinal disks and I think there are little hearts forming. I have been candling all the eggs and they are definately on different schedules. My question is where should they be at right now developmentally and is there any way to tell if they are still alive? I think they all are alive because I have seen marked growth of them from small germinal disks to large germinal disks. I read online that an infertile egg has a germinal disk of 2-3 mm and a fertile egg has a germinal disk of 5-9 mm. Two of my eggs, those that I collected Saturday, have large germinal disks and are fertile and growing. Any help would be appreciated. One more question. I have been spraying the eggs and there is a wet sponge in the incubator with them. Is there a better way to control the humidity? Keep in mind, I do not have a professional incubator with temperature or humidity control.
Thanks again
brettg117

 

[Ms.FuzzyButts]

Here is a link to candling photos. It's chicken eggs, but should give you some idea of what you should be looking for in a developing egg.
https://www.backyardchickens.com/forum/viewtopic.php?id=261876&p=1

 

[saladin]

First suggestion: next time collect the eggs and set them all the same day; it just makes life so much easier.

What type of ducks? If muscovy then you need to provide a cooling-off period each day. Otherwise, it sounds like you are on top of things.

 

[brettg117]

I'm pretty sure they are just mallard eggs. We have no Muscovy or any other type of duck here. From what I read, they aren't goose eggs either. I have seen marked growth in the eggs since I last checked them. They have gotten bigger and I see a little heart with veins on some of them. This is my first time though so I hope to learn from this and do it better next year.
Thanks for your help
brettg117