You have at least done the right "beginning" thing, getting it out of the sphagnum moss. You can go back and research numerous posts (several by yours truly), stating why Phal. are sold that way and what needs to be done as soon as you get home with a plant from a big-box store. It all depends on how fast that mounted Phal. dries out as to how often you water it. Even though my mounted ones are all outside under trees (several folks think that is a sure way to kill one
) and I have perpetual high humidity, I water mine every other day when the temperature is between 80-90 and every day (if I can) when the temperature gets above 90.
