Your phal is dehydrated . I would not mist the roots with fertilizer several times a day... mist only with plain water. I personally do not like bark mix for phals..especially near rootless phals. I find it too drying.
I have moistened aerial phal roots and and put them in the medium. Some will say they willl rot, I did not find this to happen. I grow semi hydroponically now ,and if I had to switch to another medium it would be loosely packed sphagnum moss with broken styrofoam peanuts mixed in and at the bottom of the pot. Pot size is important too, with little to no roots , a 4inch pot might be too big. Pot for the root size not the leaf size. Good Luck !