Same as chickens, but for 28 days instead of 21. So 40%-45% humidity for incubation, then on day 25, instead of day 18, increase to 55%-60% humidity.
I have a forced air LG, w/turner, so I set my temp at 99.5-100.5F. If it goes up to 101F, I back it down a hair. Even with forced air, temp will vary slightly from the floor to the egg tops. I put my thermometer on top of the turner cups, so it's about 3/4's, or a little more, of the height of the eggs. Mine's an old style turner, (the one with the prongs to hold the eggs) so the top of the turner cups is a little higher than on the newer turners.
For still air, you want 102F at the same level as the tops of the eggs, very important to check temp at that level. Not the middle. Not the bottom. AT THE TOP.
The shells of guinea eggs are thicker and harder than chicken eggs, so they do fine at the same humidity even though they incubate longer. The thicker shell slows evaporation a bit. They really need that slight increase at the end, though. Don't go too high, you don't want to drown or suffocate them.
