Have you added in water throughout incubation? I only ask because, I use a mix of perlite/vermiculite. Last year, towards the end, I did have to add in some warm water. I put it into the corner of the tubs so that the water never hit the eggs, but it did Up the humidity. Maybe this is needed? This is something that I just expect when incubating; I don't think that there's a substrate out there that never requires some adjusting. Sorry that you're having dryness though.. I know that incubating is a harrowing experience no matter what, at least to me.