How many on here are doing their first hatch? With shipped eggs? Keep in mind that shipped egg hatch rates of 50 % are considered good , by people who have been doing this for a long time. (Yes, better % rates do happen, but shipping IS risky) I practiced, and practiced on cheap, local eggs till I got it down. It did take several tries, to work out the kinks. When I got really good at it, then I ordered a cheap set of shipped eggs. Now I am getting eggs for my keeper flock, but I still refuse to pay some of the crazy prices. There is good stock out there, often better than those going for the crazy money. Patience, research, patience.
Also any cracked eggs are a potential venue for bacteria to spread in your incubator, if you chose to try to seal them, watch them closely, AND touch them LAST just in case. Incubators that have also been used to hatch in should be thoroughly disinfected between uses for the same reason.
For those of you turning by hand (I am, my older eggs), wash your hands before you handle eggs every time. I have a turner, but it is not plugged in yet since my eggs were shipped and some of them are very dark. I know a couple of the light eggs had loose air cells so I'll wait till I candle at 7 days to plug the turner in (the older eggs will be in the hatcher by then). That will give any lose air cells a chance to heal, hopefully. I don't ever lay shipped eggs on their side just in case.I set in the hatcher in a plastic egg flat since it can be disinfected for repeated use.
I don't have any waterfowl, never heard of dry hatching them. I have to add small amounts (1-2 cc) of water to my Hovabator to keep humidity levels up to "Dry hatch" levels of about 30%. My hatcher is a Reptipro 5000 and I keep a very small stone creamer pitcher (about the size of a shot glass) in it. The cabinets don't lose humidity as much as the Styrofoams, so if I have several hatching at the same time, I'll take the water out all together to keep it under 70%. I'm still getting used to the Reptipro, but I had a good Easter hatch with shipped eggs, 23 set 19 went to lock down, 15 hatched. 2 probably quit before lock down (I keep them if I'm not sure and they don't smell bad) 2 just never pipped. (you can also gently drop in a glass of very warm (95-100 degree) water and watch for them to kick, it's cool but I am not patient enough to watch for the lazy ones.)