I'm using a forced air Hovabator with an egg turner, loaded with 42 chicken eggs from 3 separate sources, all with very good roo to hen ratios. Eggs were incubated within 7 days of collection, and were kept in room temp conditions before set. I resisted the temptation to candle early on, and monitored temp and humidity regularly. (Up to 5x per day as they are in my little classroom on our first floor. lol.) Temp has been consistently between 98 and 100, without going over 100 at all. Humidity has been right around 50% for all ten days. I DID carefully wash off some dirty eggs with warm water before set, which I have not done before, but I read so many comments on here from folks who do wash, I figured what the heck. SO, I am completely at a loss. I candled and found what seems to be a clear majority of eggs with a blood ring around the interior circumference. (As well as no veining in these and just a floating blob of material inside.) Sorry for not adding photos, but there's plenty on here that look exactly like mine. Because the eggs were collected from 3 different people, and I am certain all three sources are feeding their chickens very well (including mine ) that seems to reduce possibility that it has to do with roo and hen nutrition, or handling issues (if most eggs from one source had problem I would suspect something about the handling of those eggs or something about the source.) So, clean incubator (run 2x last summer) no handling after 'bator loaded, so no bacteria introduced that way, no temp/humidity fluctuations... What am I missing? If anyone has experience with this, I would appreciate any advice, tips, ideas. My only thought is to go back to good ol' dirty eggs for the next run.