In nature, phals tend to grow bare-root, clinging onto the branches of trees in a humid environment. We put phals in pots to keep the air around the roots humid.
I grow all my phals is LECA now (just switched over from red lava rock as I like the way the LECA looks). Seedling phals without much of a root system get a topping of NZ sphagnum moss to encourage root growth. I use basket pots so I can see the roots and still allow nice air flow to the roots. I put the basket pots inside a clear plastic container and when I water, I fill this container up, let it soak, then dump the water out. If you aren't having success with either bark or sphagnum moss, this is a nice alternative.