Hi all, I've inherited a 10 gallon tank at work and have it on my desk. Has 4 tetra, 3 of them have what I think is cotton mouth. They have had this for a while as I've noticed on them months ago before I got the tank. I've dosed 2 times with Jungle Fungus clear about 2 weeks ago and they still have it. Is this cotton mouth or something different? I would like to add a couple more neon but not until this is cleared up. They are all acting normal and eating very well. Thanks!!