[Stefka]

Hi,

I've bought this orchid last week and i've noticed black spots at the back of one of the leaves. I am totally new to Orchids and I have no idea what it is.

This leaf has also become yellowish within a day. I've placed this orchid by a window facing west-north so the sun only comes out late on it. it is 4pm now and the window is still in the shade. And also the weather isn't that good in England.
ive only watered it once since I've got it. the side with the spots is the one facing the window.
Any kind of help would be much appreciated as i'm not sure what is the problem.
Also I've noticed that quite a few roots are coming out. does it need repotting?

Many thanks,

Stéfka