I've only done substrateless, but my humidity is always at 99%-100% and all my clutches hatched out fine. I only had one egg get mold, but it was a boob egg and only the boob part molded. With the perlite, just use a lot of substrate and water (the water will drain to the bottom), and keep the humidity as high as you can while keeping the eggs dry. I like uing egg crate with perlite so the only moisture the eggs get is from the humid air. Give me a call or an email if you have any questions along the way.
thanks for the info. i got the egg crate on top of the perlite. so the way im doing it is good... question, what do u use for substrateless ? (egg crate and water ?)