I always hear mixed with potting soil, is there any reason? i've always just kept them on the fiber, never mixed, just curious, i'm hoping to get some more cresties again, i've got 2 reptariums just waiting, people dont like them they say they dont keep humidity, well that's why you Mistyes it's more work but who doesnt' check in on their crestids more than 3x a day? hehe