i had regular neon tetras before in my 10 gallon. They did fine but all of a sudden they started going see thru color at night time, i though perhaps they were sleeping, then in morning they would be nice blue and red colors again. This went on for about a week then they got these white spots which i thought was ich but LFS told me it was neon tetra disease. I asked how to cure they said feed them better. I feed them well, that was not the problem. But there is no cure for neon tetra disease from what i have read. I would QT them if you could to observe them for a few days and see if they have any symptoms of neon tetra disease or fungal diseases.