First of all, please quarantine your fish. I did a two week quarantine when I added new rummy nose tetras but it wasn’t enough it seems. As I added them I’ve been slowly losing fish at least once a day. Seems to have slowed down though.
I lost a rainbow to whatever this disease is already. Can anyone with some experience help? I assume Columnaris so I’m dosing Maracyn. I’ve had these rainbows for a year now. No issues until I introduced the new fish. I’m only seeing this on the rainbows. 75g tank.
pH 6.8
Nitrates 10
Hardness 300ppm
Nitrite 0
Ammonia 0
KH/Buffer 40ppm
Water Temperature 77