Are my coelogynes sick? (yellowed leaf and yellow/brown spot)
 

Coming up on 2 months now I went to an orchid show and got 9 new orchids, 2 of them were my first Coelogynes, a flaccida and a rochussenii. The flaccida looked good, but the rochussenii didn't look very good at all, even though it was a very standard price and not cheap. I only got it really because I had seen it on the site and really wanted it (and it was the only one there).

I repotted the both when I got them home, which I later read they don't take to kindly, and I put them in fine bark. The rochussenii had only 3 roots and they didn't look great, 2 have since died, but 1 kept going and it got a new one (I know this as hubby knocked it over and it came right out the pot :( ).

The flaccida looked rootwise, but since then almost all visible roots have died, 1 is covered in mould but seems still alive.

It is only this week that their leaves have started to get worse, the flaccida had great leaves but now has a brown/yellow spot developing (see pic), and the leaves have yellowed, and the rochussenii has the one leaf that has very rapidly become completely yellow with just a couple of green rings in it. I sprayed the rochussenii yesterday with fungus fighter, but I am not at all sure this is the right thing.

I am guessing I should remove the yellow leaf, but what else should I do? I know it is coming up to their rest period could this be at all related? I have had some problems with mould in the medium of a few of the orchids, even though it's fresh, can fungus fighter spray deal with this? The directions talk about spraying on leaves. What might the mark on the flaccida indicate?

Thank you for any help (I know these aren't really beginner orchids, I just really loved the look of the rochussenii).

Oh, I forgot to say, first two pics are of the flaccida, and the other 3 are rochussenii. I have been keeping them fairly moist, but not soggy.

it appears your rochussenii is going dormant. I have one myself and it dropped all its leaves. I reduced my watering and left in a shaded area of my greenhouse. Fast forward 3 months, I have new growth and started to water/fertilize more regularly.

I'm not sure it applies to all Coelogynes, but I also did read that some don't like having their roots disturbed - so yes, re-potting may have had an effect on them.
Other than that they can also be temperamental about light. They like good light but not direct as this can scorch and mark the leaves.

Here's a couple of links for you to peruse.

Orchid Societies Council of Victoria Inc

Coelogyne flaccida - Orchids Wiki

Coelogyne rochussenii - Orchids Wiki

Cool-Growing Coelogyne Culture

Though I'm sure someone more qualified will respond in time, if not also try reposting your concerns in the "Coelogyne" section of this Forum.

What I DO know about Coelogynes is that you should check the yellow leaves with a 5X magnifying glass for mites. I had one start yellowing its leaves and they started dropping off and when I finally checked it was epidemic mite city !!! The first never-to-be-forgotten totally different mite sign I've ever seen, and I get them frequently on my Ctsms !! I thought it was some kind of environment issue !!

Just check, if only to eliminate that as a possibility.