Last year I mounted a Phal. schilleriana on EcoWeb/EpiWeb, a type of synthetic tree fern fibre. It's been growing well, but the roots look a bit constricted by the tightness of the weave as they grow in it. So this year I'm trying a Phal. bellina on a slab of Matala pool filter material. I choose the most open of the four weaves they have (the black filter) to see if it accommodates the roots any better. Seeing how open the weave is, I probably should have gone with one of the two middle coarseness pads. It still holds some water, but not as much as the EcoWeb/EpiWeb.
Phal. schilleriana on EcoWeb/EpiWeb
The back, showing the weave
Phal. bellina on Matala filter pad
The back, showing the weave
Cheers.
Jim