Epidendrum Mabel Kanda 'Miyao' question

[VickiC]

Hi,
I have an Epidendrum Mabel Kanda 'Miyao' that I had potted in a bark mixture (bark, charcoal, perlite,LECA, etc.). About 2 weeks ago, I saw that it had started new growth so I repotted it in S/H. I noticed last night that there was a whitish tint on part of the top layer of Prime Agra, so I assumed that it was a fertilizer buildup and that I would unpot it and do the "LECA boil method" today to remove the buildup, then repot. After I inspected it closer, I saw that one of the old, very small aerial roots had a whitish tint to it but also had some white fuzziness on it, as well. I unpotted it and soaked the roots 3 or 4 mins. in peroxide. I plan to repot it this morn., but I don't know whether to go back to S/H or pot it in a fir bark mixture again. I have been waiting for this new growth because I really wanted to get get in S/H, but do you think that the S/H environment is too damp for an Epi, or not? I will repot into which of the two mediums you suggest.

I would appreciate your advise,
Vicki