It's always the expensive ones who rot!

[fishmommy]

I am having my very first orchid illness and of course it's this obscenely expensive paph I bought this summer!

I have a couple other paphs with no problems. I use R/O water, keep them in the shade, etc.

When I bought this one it had a couple of small black irregular patches on a leaf that were sort of sunken.
Over the past few months they multiplied slowly.
Suddenly last week, two leaves turned yellow, then black, and limp.

I bought Physan 20 and am currently soaking the plant in a 1tbs/gal solution. I cut off the two dying leaves but left one that looks good except for a few spots.
When I depotted and rinsed the roots prior to soaking, I found a weird gelatinous blob - clear - clinging to a root and disposed of it after almost barfing it was so gross.

Anyway, am I doing the right thing? I plan to repot in physan soaked bark. Do you think this is going to cure my plant? What the heck was the jelly thing? It was definitely not a rotten root!

Why do the expensive ones do this