I have hatched CCL at much lower humidity just fine. What I have found is LOW humidity does not seem to make an impact for the negative in hatching, but HIGH humidity will drown more chicks.....I called the company and they didn't think it should have that much difference either. They may have to send me a new top. I am also trying to heat up that room (can't heat the whole house that much) to see if warmer air being drawn in from the vents at the bottom of the incubator will make a difference. I had an email from Richard Jordon where my eggs are coming from and he says to set the eggs at 40-45% humidity for the Cream Legbars. The humidity readings are pretty much all the same within a few degrees now, so that shouldn't be a problem. Just working on the temp.