Question on hatching marans

[Mrsfoote]

So I have some maran eggs in the incubator as well as some other dark breed eggs...everyone says they're really hard to hatch SO i was wondering from everyone whose had sucessful hatches....what can I do to make them less hard to hatch. I have them in a brisnea octagon so most of the guess works theres done for me.

 

[jarodw45]

Just hatched 4 out of 7 in a Brinsea Eco 20 and the three that didn't hatch were developed but didn't pip... I had humidity issues because of our heater in the house...