I am posting this method of potting in sterilized moss. This is how I pot mine.
16 qt pressure cooker and 4 bags of Better Gro sphagnum moss (if you can get NZ sphagnum, even better)
Growing Phals in moss is perfectly fine if you follow a few simple guidelines.
Tom at Stones River Orchids / Nashville, TN was at our OS meeting just back from Taiwan and he had lots of good information regarding Phals and media.
He's been growing and breeding Phals for about 30 years. One of the biggest "hello" moments he had in discussing media issues with the TWN breeders is that if you have a plant that has been happily growing in one kind of media and you switch, it can set the orchid back for several years and sometimes permanently if the orchid does not "like" the media you choose.
With that said, a lot of his presentation was based around him changing over from a bark mix to straight moss. I know...you probably think he is crazy but he gave specifics. You know how a lot of people say "do this" without giving you the full picture? Well here goes...directly from my mental notes from his presentation.
First of all, he said a lot of folks fail with moss because they over water, over pot, and do not prepare the moss correctly for use.
Moss must be soaked in a sterile like solution (some people pressure cook it to fully sterilize it) but he soaks for 24 hours in Consan Triple Action 20 then rinses the moss and soaks again (i didn't catch if the 2nd soak was in the sterile soln again or in water).
2nd (and this came straight from a TWN breeder)...Phals need the security of being tightly packed in a pot...(I KNOW...it sounds crazy). He carefully chooses a pot slightly bigger than the root system - you can trim off dead roots. He takes the orchid and carefully curls the roots (if necessary) and takes a handfull moss which has been carefully squeezed out and fluffed up and then squeezed again and puts a section around one side of the roots and another section around the other side.
He takes a little moss and puts it in the bottom of the pot (he uses plastic) and carefully shoves...yes he shoved it in the pot.
Now the trick...He packs the moss tightly around the Phal carefully keeping it about 3/4" to 1" below the top of the pot. The moss never comes above 3/4" from the top. This is VERY important.
Once completed, he does NOT water...no water for about a week. He said it is very important for the plant to be secure in the pot to recover from the potting process and watering it is not necessary. There is enough moisture in the moss.
Now he said the next part is critical to the success. When you water, you only fill the pot from the top of the moss to the top of the pot. You DON'T saturate the pot through. Then you LEAVE it ALONE until the next watering...which for him in Middle TN can be 2 or 3 weeks. Also, with the moss he fertilizes much less too (maybe once ever other month only during active growth).
I didn't have a chance to ask him how he monitors the moisture content of the moss, but I imagine that he uses the weight method. Heft the pot to feel the weight.
Anyway, the point of all my rambling is that when you change from one media to another it is important that you consider how far back you will set the orchid.
For example, he said that he is in the process of switching from the bark to the moss and has been for over a year and he definitely noticed that some will need longer to adapt to the new media.
Also as FYI, this does not work if you have an automatic misting system. You absolutely cannot mist the phals in the moss because it messes up the watering schedule. The moss must be allowed to slowly dry out (of course not bone dry) before the next watering.
Good luck! Mine are doing great in moss!