It all comes down to your environment and if you are seeing negative changes. I don't like spag because it doesn't agree with my orchids, it isn't sold here but the new plants are shipped here in it. Take it out inspect the roots and put it into a media that doesn't hold water that long. And hold off the watering for a bit til you see the roots take on the silver colour that says it needs watering. Hope that helps.
Take a look-see at these if that helps more: Phalaenopsis Orchid Care | River Valley Orchidworks &
Orchid Growing Mistakes to Avoid | River Valley Orchidworks