It's a FOWLR
tank. I just did a 15% water change earlier today. I checked for that also thinking maybe I had a spike but everything was fine. I use water from the LFS
. I was reading that it might be whirling disease. I've had him for like a month already and I did introduce 2 new fish yesterday but they are fine? Any ideas? And is that something that could happen to my other fish as well? Thanks.