HELPFUL HINT--- Dont just take my word on this it has been covered here before and works like a charm! So search for the string and you'll see-----
When you go into lockdown place your eggs in trays so they are upright--- large end up and stay that way! ---- Do not lower your humidity!
Here's the reasoning--- many chicks die while trying to pip/zip by drowning--- yes i typed the word drowning! Try and follow me here and we'll look it over so it makes sense--- the chick is in its warm toasty calcified egg ready to hatch right? lets look at egg structure and anatomy--- shell, outer membrane( the 1 thats against the inside of the shell) inner membrane, amniotic fluid which supports and lubricates the chick, and junior who wants to get outta here cause its gettin a lil cramped!
Keeping that in mind....
chick goes to hatch--- has to break thru inner membrane 1st( this triggers a response where the chick starts absorbing all the blood that was in this membrane (it works as the embryo's lung) so now no more oxygen rich blood unless it breathes right? still have to break thru the outer membrane and shell to do that--- even if the lad manages this without dying from asphixiation( lack of oxygen) it still has to zip all the way( or nearly all the way) around the shell---- now if its lying on it's side where does all that amniotic fluid go? The lowest point in the container! if jr is a lil backward, or the fluid cannot drain out of the shell then he drowns in his own amniotic fluid!
set the eggs upright for lockdown and this is what you get--- all the amniotic fluid stays at the lower part of the shell so jr has plenty of time to extricate himself from the egg without drowning as well as it helps delay or prevent the membranes from drying up and "shrink wrapping" jr into the egg and preventing him from hatching.
keep your higher humidity to 1. increase the moisture content of the egg wall and thereby make it softer and easier for jr to break through 2. keeps the lazy lack-a-daisical jrs from drying out and getting "shrink wrapped" as easily.
This will improve your hatch rate and has been proven time and time again--- I dare ya to try it, and you'll see for yourself