Incubator. It has been requiring recalibration d/t the styrofoam bottom becoming degraded and losing water/heat. Overall though it was never cooler than 98 degrees fahrenheit and humidity at its lowest was 49%. (predominant readings were >101 and >65%) I candled YESTERDAY when I had to remove the eggs to clean the explosion mess and there were a couple that do look like there are chicks in them, I still find the dark brown ones very difficult to tell. Some of them seem to be a solid mass of ?? in there... I read on other threads about the veins. I did not see veins in those eggs so they're probably junk, yes? Gosh, this is a really bad first experience!
I would never trust a float test, but no, it doesn't kill them to do one. I've personally
tested it by soaking them for 60 seconds in an antibacterial solution, and now many do that with no problem.
The problem is with the temp variations as low as 98F and as high as 101. They should be at 99.5F throughout. People have power outages, and I've heard of ones as much as 13 hours, and theirs still hatched, but that's different. Humidity can be an average, but not the temperature. Hens get off their nests for sometimes hours, but when they get back on, they're right back to 99.5F and steady until the next time they get off.
I've hatched over 500 silkie eggs this year, and hundreds in prior years, and I have
never had an egg explode. Yet, you had two in the same hatch. That's probably due to one that was dead right away and went the whole three weeks cooking in an incubator is my guess.
Just assuming the temp was low more than high, that could delay them hatching.
Having an egg explode is a problem, but provided no eggs were pipped (poked a hole in the egg), none of that could have gotten into their egg.
I'd give them one more day.