I heard that with reptile eggs that the lower the temp during incubation the more females you'll have. And vice versa for males.

Like 88 for lots of females and 91 for lots of males.

I can't remember where exactly I heard it (I think it was animal planet, but I could be wrong)...

I would say my lowest would be 87 though (I keep mine on 89 normally).

I hope any of that helped