I use 100% sphagnum moss in the pot when transplanting from sphag-in-a-bag. There is less adjustment that the plant must make as opposed to switching from the sphag in the bag to 80% bark. Also, I find it easier to monitor moisture in sphag by color and texture. (Keep it on the dry side) I'm always guessing when using bark. You can move to bark later once the plant is established.