I use pure long fiber sphagnum on all my Nepenthes. I live in a pretty dry area in southern California so I guess it would work for me, but i do know a couple growers who also use pure lfs that live in more humid areas. There are also a couple of growers that use it even in their greenhouse grown plants. I think the key is to let it dry a little bit in between waterings. I am also growing a couple of plants in pure living sphagnum with good results so far. As long as you have good air circulation and you let the soil dry a bit before watering, you would have happy plants. My advice would be to experiment with a plant or two that you wouldnt mind loosing, worst case scenario, and see how they do.