For me and many others, phals usually really take to s/h. I also have a brassia and a sharry baby in it and they both love it. You also get the best results with any orchid you chose to put in s/h if you wait to see new root growth going on before switching over. I'm still a newbie at this so thats really all I can suggest. I hope that helps a little!
Katie, semi-hydroponics is not just a form of "potting". It is a culture method utilizing a different kind of medium, a different pot design, and a different watering and feeding regimen compared to traditional methods.
As Sarah pointed out, timing of repotting is a major key to success.