Aerangis articulata/spots on leaf

[FinnBar]

I noticed this morning some spots and slight yellowing on the bottom leaf of my Aerangis articulata.



no signs of a new leaf. two new roots have started since i got it and mounted it. it's placed inside my tank in high humidity where it's sitting about 5 inches away from a small fan.
can anybody give me instructions on treatment? also, is there a risk of this spreading? i usually soak my Aerangis in the same bucket.. big mistake?

i'm posting a photo for the first time, i'll see how it goes..