Unhappy Cirrhopetalum (Bulbophyllum) - yellow leaf, black spots

[Vrana]

Hey everyone. Just two weeks ago I got some orchids in the mail. Two of them are doing well, but I'm having some trouble with my Cirrhopetalum Sanguineopunctatum (which I understand is closely related to a Bulbophyllum, in that it was until recently classified as such - I mention this as I assume the culture is similar.)

I noticed some minor spotting on the leaves when I got it, and the plant has since gotten worse. One of the leaves is yellow and spotted and in really bad shape, and there's some black spots and brown tips on the other leaves as well. I've included some pictures - the first I took a couple days after I got it, just after putting it on a new mount. The other three are of the plant now. I did notice in comparing the pictures that the pseudobulbs are rather shriveled - I'm guessing I under-watered it as I took a look at the roots and they look healthy (they're firm and pale green in color). I have it soaking in a pan to re-hydrate as I type this, but I'm guessing not watering enough didn't cause the other issues.

I currently have it growing in a new vivarium set-up (just plants for now, no animals other than some springtails) so the humidity is between 60-80%, and the temp is between 70 and 85 or so. I wouldn't mind taking the plant out but I don't think I'd be able to provide enough humidity for it otherwise.

I could really use some advice here - I've only actually seen pictures of this plant in bloom, but it's wicked cool and I'd hate to lose it. I've already done a bunch of searches on these forums, but it seems like I might have a whole host of problems here and I'm at a loss for what to do. Thanks in advance!

[King_of_orchid_growing:)]

That yellowing leaf could be an old leaf that has run its natural course.

If you're getting new leaf spotting, I'd say to try providing better air circulation.

[Vrana]

Yes, one of the newer leaves has black spots on the underside as well. I noticed there are black spots on my masdevallia discoidea that's in the same tank as well... I've already talked to my b.f. about putting a little computer fan in the tank so hopefully that'll help. In the meantime, should I remove the yellow leaf, or let it fall off on it's own? Also should I treat the plant with anything? I was hoping to avoid any chemicals (fertilizers, pesticides, etc.) since I will eventually be introducing some lizards to the enclosure.

[King_of_orchid_growing:)]

The improved air circulation should kill off the pathogens without using a fungicide, (it is most likely a fungal problem).

I don't think you need to remove the yellowing leaf, it's on its way out anyways, it'll drop on its own.

The leaf with the new black spot, I'd leave it on the plant. The plant will need as many good leaves as possible to recover from the disease.

[Vrana]

Very good to know. Thank you so much for your advice!