Need Help with black spots on Vanda (PICS)

[cbloveday]

I have started to notice black spots on my vanda. They seem to be getting worse. They are concentrated on the top leaves. I believe it is a fungus and need a vanda experts opinion.

Growing conditions are under indoor light. I water only the medium daily or every other day. Roots look like they are propagating and firm. I have only had 2 months so no blooms yet. Temp is 70-75 during the day and 55-65 humdity. I have humidifier in room. I fertilize very lightly every watering with Hausermann's Fertil-ade 15-5-5. I have physan 20 and was wondering how I should apply it if you believe it to be fungus.
Should I use diluted strength like 1 teaspoon to gallon and spray leaves?


Also the lower leaves have a chalk like appearance.

Please help, this is my only vanda!!!!