I wouldn't recommend placing a heat pad underneath for heat. Not reliable. I would go with room temperature. Safer and way much lower chance of killing your eggs. Ultimately what's most important is minimal fluctuation in temps.
Perlite can be trickier as in getting the right amount of dampness. Perlite doesn't retains water as well too. If you do use perlite, I would recommend checking the inner part of the lid for moisture and wipe it off. You could drown your eggs if the droplets get on your eggs. What you want is just enough humidity where your eggs aren't dimpling (they will, expectedly, dimple during the last few days before hatching though) but there's no moisture directly on your eggs, either from condensation or too moist of a substrate.
Sphagnum moss as a medium, is debatable for some species. I have found that using a thin layer of sphagnum to cover the eggs keeps mould at bay due to the acidity of the moss. Some people worry about the acidity thinning the shell of the eggs but I've found dramatic differences between a clutch covered with sphagnum and one which wasn't.
Don't worry about bad eggs too much. More harm can be done removing them. If a good egg is good, it will not get mouldy.
The Herp Room
"The day I tried to live, I wallowed in the blood and mud with all the other pigs" - C. Cornell
Last edited by Vanan; 04-16-04 at 05:51 PM..