Black stuff on stem of Vanda

[Pinkeed]

I don't know if I need to worry about this or not. As the leaves of the Vanda are not yellowing or anything and the roots look fine. I got this Vanda about 2 weeks ago. I didn't notice until I got home that it had some black stuff on the bottom part. The black stuff seems to have moved up the middle of the orchid. I sprayed it with hydrogen peroxide today and yesterday hoping that would kill whatever it was. I think it's working, but I'm not sure yet. I am guessing this is a fungus or mold. And yes I need to cut the flower spike, but have included it in case it helps.

This is my first Vanda. I usually stick in a bucket in the morning for 15-30 minutes. The stuff around the roots is Synthic (it helps keep them moist during the day). I feed it with Hausermann's 8-4-8 Orchid Fertilizer every second or third day (depending on when I remember). Temperatures run 68-72 degrees during the day and it lives above the sink so the humidity is pretty high. Not sure of the exact amount as I'm waiting for a new hygrometer. Last time I checked the room in general it was 40%, so guessing that over the sink is more like 50-60% (but I don't know that for sure).