Are you using fluorescent lights in your room? If not, and your room is "fairly dark" and "nice and shady, never bright," it sounds like there isn't enough light for even a phal. In the few cold months I have, I bring them inside under fluorescents, 4x40 watt "daylight" bulbs. There are three shelves, with the plants about 6" from the bulbs, and it's really quite bright. In the summer, they're outside under shade cloth, right alongside my oncids and dends, etc. In my experience, phals do better with more light than you'd think "low light" means. When they are getting the most light they can use -- but not so much light as to burn them -- some hybrids get a hint of darkish reddish on the edges of the leaves.

As to potting material, it depends on what works for you, as well as what kind of pot you're using. I use terra cotta pots, some with extra holes and some without. Plain packaged medium orchid bark doesn't work real well for my phals. I've used straight sphagnum moss for a couple of years with good results, but I've started experimenting with bark mixed with a bit of sphagnum and I think I like that even better. It really all depends on what works for you.

To avoid crown rot, don't allow water to remain in the crown; water early in the day, so whatever has collected in the crown evaporates.

Phals are my favorites... Good luck!