Yes keep the temp exactly the same. I've tried about every medium there is for holding moisture for hatching and a good sopping wet rag seems to keep it the highest. Lots of things absorb moisture but some things release it better. I used to use sponges but they tend to absorb but not release as well. I have a pan of broken clay pot pieces in the bottom of my hatcher and put the wet rags up higher., plus the automatic waterer. Of course mine is a big GQF so I have room for all that. I think Hawkeye had found some way to add water without opening the unit but I don't remember how. You could use a big syringe with a plastic tube attached to add water.