I incubated guinea eggs with my chicken eggs, so 99.5 in a forced air. Humidity at 35-45% for the first 25 days, then increased to 55-65% in the still air hatcher. I had some pips when I moved them to the hatcher at the end of day 25, since I didn't expect any to hatch until day 28. The 8 that went into the hatcher took 3 days to all hatch. Started with 12, 4 were clear, 8 hatched and doing well, so 100% for the fertile ones.