I generally use sphagnum moss for my larger Platycerium plants and finely chopped sphagnum (10 seconds in a blender) for my sporelings. Recently, I was able to purchase a big bag of peat moss from Wanna and am amazed at the health of my young sporelings after transplanting them from sphagnum to peat. Every single one 'greened' up and the overall healthy appearance has 'sold' me on the peat! I've just started a few new boxes of spores on peat and will see what type of results I get. My Selaginella and bird nest ferns are usually grown on coco fiber cubes.