Yea I don't want my temps to go past 89 . But I I'm nervous if I drop to 88 that one of the tubs maybe at 86 and idk if that's gonna be to cold or not .
Do you have a fan circulating the air in the incubator? If not then I would suggest wiring a small computer fan in there so that the ambient is the same through out the incubator. There really shouldn't be too much variation from tub to tub if your setup is correct.