Ray B wrote:
Tennis, you might want to consider a slab of EpiWeb. It looks similar to
tree fern, but is less dense and unlike treefern, does not absorb water at
all in the material, but does hold droplets in the web.

I have just attached some tolumnias to it, and have several
neofinetia/vandaceous crosses that seem to love it, and have some small
oncids that seem to go for it, too.

I may go that route for some other things later (running out of treefern
slabs quickly!), but I really think the brassavolas want their roots
just hanging out there in the air. I'm anxious to see how the clay does.