It’s hard to say … have you hatched before, what kind of incubator do you have, were the eggs shipped or did you pick them up from a seller? If you got them fresh from a seller and have hatched with good results and have calibrated hygrometers and thermometers besides the the readings given by...
No apple cider vinegar, giving that is basically an old wives tale sort of thing, and it tastes bad and is unpleasant for them. If you put anything in the water it could be a poultry vitamin or booster like nutridrench or rooster booster.
How many chicks do you plan to raise? There’s nothing...