low temps will kill some embryos (like turkeys).. so you don't want to go too low..
without knowing what kind of incubator and what kind of eggs I would tend to go with the 100.8.. it's still in the acceptable range however it leave pretty much no room for temp spikes
if those were my only two choices I would go for 100.8 for incubation then drop it down to 99.0 for hatch
Its got a fan and its for chickens. I think ill keep it where it is. The temps fluxuate between 99.7 and 100.8. Humidity is steady at 33%. I think it looks good and im ready to start incubating.