Was viewing my local classifieds and noticed someone giving away 8 neon tetras so I thought score I need to bring my tetra numbers up currently only have 10 anyway noticed one has what looks like white cotton on it's mouth I asked her how long it's been like this she said 4 months is this cotton mouth disease and is it treatable?*

Currently have all In a quarantine tank and it seems fine but never seen anything like this before I've read cotton mouth kills quickly though so I don't no if it's that seeing as it's been like this for months,*7 other tetras are fine looking