U-Line's prices seem pretty fair, too. Most small garden shops will charge you $6-8 for a small bag. A 4 cu. ft bag from Southern States or U-Line is more economical if you are incubating several clutches.

The number one mistake people make with incubation media is to get it too wet. I mix 3 parts coarse-grade vermiculite with 1 part perlite (optional). I weight it and then add 50-70% water (by weight). I vary the amount of water by how dry the vermiculite and perlite are to begin with. This isn't something I can easily describe so you should err on the side of using less water. You can always add a little bit of water later if necessary. As an example, I will measure out 750 grams of vermiculite and 250 grams of perlite and then add 500-600 grams of water.

Also, don't put a lot of holes in your incubation box. I have one hole in my boxes. In the past I used two. Too many holes allows too much air flow and the eggs can get too dry.