I open the door every other day for about a minute.
there's your problem.. you should open that door several times a day
the Reptipro doesn't have "vents" like other bators.. so you need to open the door several times a day for air exchange.. otherwise you're depriving the eggs and hatching chicks of oxygen..
I open mine all through incubation (hand turning eggs) as well as several times a day during hatch.. and I have had excellent results
just remember..
hot air holds less oxygen than cool air
humid air holds less oxygen than dry air
developing embryos (and especially hatching chicks) NEED oxygen
hot humid air doesn't hold enough oxygen for hatching chicks and developing embryos
I even drop the eggs down to the lower shelf at hatch since there is a temperature gradient.. so if the top shelf is reading 99.5.. I lower the eggs so they are hatching at 98.5 temps... that plus increased humidity works beautifully for most birds..
lately since I have been doing staggered hatches I haven't been raising the humidity at hatch since I am still hand turning other eggs.. as the eggs start to pip and hatch they are naturally raising the humidity enough .. I've even opened the door in order to remove chicks, shells and to lower the humidity a bit for the incubating eggs.. now that won't work as well for ALL birds.. turkeys for instance require a higher hatch humidity.. so adding a pan of water to the bottom still allows me to open the door several times a day and the humidity goes right back up as soon as I close the door
during the average day I open the door at least 5 times a day while I candle eggs, move eggs around or turn eggs.. so it's open for several minutes at a time
if you're afraid of losing humidity just remember.. it's easier to save a sticky chick than it is to revive a dead one