So about 4 days ago I got a school of 12 Rummynose tetras from my lfs for my 55 gallon and put them into quarantine in a 15 gallon. All was good until Sunday I woke up to one dead and one spinning and whirling in circles and about 30 minutes later he died too. I looked at there bodies and nothing was abnormal, their noses were even still red. I tested the water and everything was good Nitrates:5 Nitrite:0 Ammonia :0. I put a little bit of Seachem prime in just in case and left them alone. On Monday one mysteriously died also and today I just saw one doing the whirling thing also. Their noses are all still red and the tank parameters are still good. Does anyone know why this could be I’ve looked everywhere and haven’t seen an answer.