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.