phalaenopsis tetraspis with no roots

[Roberta]

I have also had considerable success with sphagnum, loosely packed, in baskets, especially wood ones. The loose sphag dries out rather quickly (the "loose" part is important, just firm enough to keep the plant stable) in that open basket. Species Phals seem to especially love the wood baskets - think of them as a three-dimensional mount. Basket should be 4 inches (10 cm) (The size is the outside dimension so the inside dimension is smaller) The small size means that the amount of sphag - or any other medium - is small, so that it does dry out fast and air gets to the roots.
The choice of medium and container, of course, depend on your availability to water, and your general conditions. It's the objective that is important - moist air around the roots with a wet-dry-ish cycle.