unknown platy disease

[themuffinbandit]

so the other day, I noticed that my platy had some white on its fin. or right by it. i didnt know what to make of this, but its definitely not right since it doesnt use its fins (ones on its side... dont know what its called). ANyways, by comparison, my other platy doesnt have that spot and is much more active. any idea what it is? I've put in some salt into the tank in hopes that the other fish dont get infected. Please let me know

[Little Embers]

Poor Thing! If it isn't using it's Pectoral Fins (I believe there called) that doesn't sound good. I not that knowledgeable on diseases, I'm sure other members will help.

I will ask though, does the white patch look powdery or fuzzy/furry?, it may be a fungus/bacterial infection. I don't know much about medications, but I would try and isolate the platy if possible.