There will be ten different recipes for this thread. But here is mine: Medium bark, charcol, sponge rock, and a little bit of peat moss which will wash out of the mix in a few months. I put lava rock in the bottom of the pot for stability and for humidity. But I live in a different environment than you. And I like a rather free draining mix to boot. Just my two and a half cents. Taxes ya know.
Whats it growing in now and how is it working?
I think you should grow this or any of you're orchids in the mix you're most success & comfortable with.
Gotta agree with Gloria on this. What do you have success with, and what is it's current health in the mix it's currently in? If it's doing really well in it's current media, stick with it. If not, maybe consider another option, but you should let us know what you think could be better with it. This will help us advise on a better mix.