That's a mystery, Cinta. I have never seen a decline in my Phal. like that so really don't know what's going on. Phalaenopsis, like any other orchid, needs light, water, humidity, (weak) regular fertilizing, open potting media (or mount), and air movement.
There is nothing wrong in re-hydrating the bark by allowing them to sit in water. I occasionally do that with selected plants, but having hundreds of them, that's not practical for me to do as a general rule. Cinta, you might want to mount one of these plants, though a compact or sub-compact would probably be better choices to mount. You would have to mist that plant regularly though. At least in that way you can observe what those roots are doing. You can also just place mount/plant in a sink of tepid water for a few minutes, (with a tbl. of fertilizer added once a month). You need to do this on a weekly basis. I have a number of Phal. mounted and they do very well mounted.
