i just recently purchased some new acei's and i am pretty sure 1 of them has fin rot. i didn't notice anything when they first arrived so it was either really small at first, or it spread within a couple of hours. he has colapsed fins and he hangs at the top of the tank. he is already in my 75 gallon with my other fish. was wondering the course of action i should take and if i should be really freaked about it spreading to my other fish. any help would be great!!