Are Rummy-nose tetras susceptible to disease? If yes, what is the name of the disease and how to treat it?
You could say that it is indeed susceptible to disease. one of them is affected by white disease or ich or bacterial infection.
To treat fish affected by ich disease, you only need to quarantine them in an aquarium that has been given drops. After that, let the Rummy-nose fish tetras in the aquarium until it heals.