I’m just curious as the bark that I bought and have transfered most of my new plants looks fine except it seems to have a lot of black developing in it faster than I would say looks to be healthy.
Photos would help. Have you only recently potted your plants? Available bark can vary widely in quality, finding good quality, hard bark can be a real challenge that is getting worse. There are several member of the Board who live in your area, who I am sure will jump in and share their experience.
Oh, and don't be concerned about pictures that come out sideways. It's a "feature" of the ancient software platform that the Orchid Board uses. (It is possible to control by saving photos to a computer, rotating, saving, and rotating back, but we are also accustomed to just twisting our necks around...)
Give some other folks a chance to jump in... I'm just the opposite, need a full keyboard and a big screen. But lots of folks use phones and can advise.
The bark is pretty big for the little Dendrobium. Right at this point you can leave it and let it bloom. What you want is a smaller container, and bark that holds the plant firmly but still has lots of air space. If you see the start of new root growth, that's the ideal time to pot.
Looks about right for the next one... can't be sure what kind it is, if an Oncidium you'll need to keep it on the damp side.