rough brown spot on phalaenopsis leaf
 

I'm relatively new to orchids (just got my first one a few weeks ago) so I'm not sure what's troubling my orchid. I discovered this rough brown spot on one of the leaves this afternoon. Could anyone tell me what could be causing this, and what I could do to treat/prevent? Thanks!

Is this orchid a Phalaenopsis? What color was the spot when it started? Where are you keeping the plant? Do you have a pic of all the leaves on orchid? This could be caused by a number of things, to high humidity, the way the plant is watered, if it is a Phal orchid, when you water it you can not get any water in the crown of orchid this will cause crown rot.

Could be sunburn. If this is a phalenopsis,keep in lower light, don't allow water to sit in crown of plant and water early in the day. Read up on these...the easier orchids to grow and very rewarding.

yes, it is a phalaenopsis.

as far as the brown spot goes, I don't know what it looked like when it started, I had an extremely busy weekend and didn't get a chance to closely inspect it until last night, when I discovered it.

here are some more photos. the other leaves look healthy (to me at least). one has a small brown spot from where a sharp root spike is growing up into it. I did find a concern, where it looks like a sick leaf had maybe been cut off but part of it is still attached and very yellow looking.

but the biggest concern... I didn't realize that it was double potted when I purchased it, so the roots have been sitting in water for who knows how long. :( I'm assuming that the grayish-brown roots are dead and rotting?

is there any hope of saving this orchid, or do I just need to start over with a new plant from a better seller?

forgot to include - I currently have it sitting in a north-facing window in a spare bedroom (I live in an apartment and all of my windows face north). we keep the temperature between 68 and 75 Fahrenheit. humidity is low to normal (probably 30-40%).

I personally don't believe that it's sunburn, as we have had very cloudy and rainy conditions for the last week or so in my city, but I know that UV and heat can still pass through the clouds so it's obviously still possible.

It does look like burn, but sun burn in a north facing window seems unlikely (even more so at this time of year).
Could some cold water have been sitting on that leaf during low temps?

The roots seems to be healthy, don't you all agree As well as all the other leaves...maybe an old leaf? Or dying prematurely because of crown rot.

I cut away the brown spot and the mushy roots and repotted it in a better pot and new bark mix. hopefully that takes care of all its issues. thanks for the help!

Since you just got the orchid it is in bloom? Phal orchids drop there bottom leaves. Is the leaf in question a bottom one? The partial dead leaf that is on the plant is probably what happened to that one. Try to get the rest of that leaf off by gently pulling on it. Once the orchid has finished blooming remove the plant from pot and all orchid bark. Reuse the pot (clean it)but not the bark. You can cut the old roots off using clean scissors( I use rubbing alcohol some use fire) place orchid in pot so the bottom leaves are just to the top of the pot, so place new bark at bottom of pot to make this happen. Place more bark around the orchid gently pushing bark into the pot so orchid is sturdy in the pot.
The orchid is at rest so only use water till you see new leaf growth coming from crown.