Black/Brown spots on Renanthera leaves

[petewall]

Hello,

I am just getting started with my orchids. I have a Phal that I took from tough shape to healthy, and I picked up three new orchids from a recent show in town.

I have a question about my renanthera. It's getting black/brownish spots on the leaves near where they meet in the middle. It's in bark with some grassy stuff on top. I water it three times a week, and it's in my office.

I've attached a picture soon after I bought it, and one from yesterday.

As a side note, I don't think it's getting enough light in my office, so I'll probably bring it home and buy a full-spectrum light for it to sit under during the winter.

Thanks for any advice you can give!