Think of is aspect of orchid growing as a multi-variable equation seeking the same answer.
The variables are the potting medium properties, the pot properties, your growing conditions, and your personal propensity to "mess with" your plants. All of them, together, should lead to the correct "answer" of what's right for the particular plant.
Try reading
THIS to get a greater feel for what I'm trying to convey. Subrosa is right, it may take some experimenting.