Poor hatch rate

[SnazzyJazzy]

I have a plastic janoel 12 incubator. Automatic turner. Three temperature gauges, not including the included one. All read 99.3-100.2, the one that comes with it is set at 37.8 (100.4). I hatched 6 black australorps on day 19/20. No problem. 12 buff eggs went in, 9 devolped. Put in three australorps, knowing I would have a staggered hatch. 8/9 buff eggs hatched in 21/22, the last appeared to have some nasty yolk sac infection, died in shell. One of the australorp never developed, the other two made it to day 21...then to day 25. Where one very weak chick hatched. The other died in shell. Te weak chick survived a week and died. Sanitized the incubator thoroughly. Twice. Two weeks ago I put in 6 austra white eggs. At day 5 they looked great. At day 14 (today) two looked great. All others stopped between day 5 and day 10. Opened up the four, no signs of bacteria. The incubator is in my bathroom, but was for the buffs as well. What could have caused this sudden downward spiral? Wrong time of yeah? Toxic fumes from the fan? I'm totally lost.

 

[FridayYet]

How was your humidity compared with previous hatches? Are you checking air cells? Is the temperature in your bathroom stable this time of year, or does it swing cold at night?

Were your Austra white eggs local or shipped? How is the health of the parent stock?

So many questions, I know. Just trying to help you pinpoint what might have happened from prior hatches to this one.

 

[SnazzyJazzy]

Humidity is the same, unless humidity from showers changes it temporarily. When I I look it's between 34 & 38%. Bathroom never gets below 72 (at night with the heater, 76 day with the heater) never above 78 (78 a/c, 76 night a/c, my first hatch was on my counter, kitchen is held at these temps whole time). Air cells looke great. Austra white came from my mom, as did the buffs. She literally lives across a field from me. Parents are all healthy and just stopped molting.

 

[SnazzyJazzy]

If it's the incubator it's really not a huge deal. It was bought cheaply and in a pinch (it was new, this is it's third time). I planned on getting a different incubator this winter anyway. But my mom was going to buy this one off me, don't want to sell it to her if it's defective.

 

[howfunkyisurchicken]

Did you calibrate your thermometers and hygrometers before you stated incubating? I calibrate mine before each and every incubation. Sometimes they can all read around the same temp, but they can all be incorrect.