So often we see new postings about crown rot, especially regarding Phaeonopsis from some of the new people on the forum. Well, let me tell you, we all should pay serious attention to this problem because none of us, old or new, are outside the devilish grip of ROT! And it isn't only Phals that one must be concerned as the attached pictures tell the sad but true story of one of my Bulbos.... We all must exercise caution when watering especially when new tender growth is present. As you can see, I've removed the damaged growth and cleaned with bleach and something similar to Physan-20 and dried out the cavity. I also used some cinnamon for whatever this will do. I only hope that the entire pseudobulb doesn't rot and that new growth will start next growing season.
I've had mostly success with putting a little hydrogen peroxide into a crown that looks like it's getting rotted, let it sit for a few minutes then spill it out.
It has worked when I see the signs early...don't know if it helps once more damage is done