did you happen to do a water change last night before you saw the heavy breathing begin? i wonder if, since water changes aren't helping, maybe something has changed with the tap water itself? any heavy rain or snowmelt going on in your area?
I didn't do a water change until today. I do weekly water changes on Sundays or Mondays. its a routine I stick to religiously. the last change before this was last sunday.
I get city tap water. but it did rain ridiculously hard for like 2 straight days in the middle of the week. However, I did not do any water changes during the middle of the week.
my 2 red tail rainbows both died within 10 hours of each other. and that was days ago.
no other fish in the tank have showed any signs of stress whatsoever. strange... perhaps these fish had a weakness the others didn't. cuz I can't figure it out. bizarre
In nature, a sick fish is lunch, so even if a fish is sick, they won't show it right away... It could be they were sick with something undetectable to the naked eye long before you brought them home. I was meaning to ask if you have any live plants in the tank... Sometimes the decomposition of plant material will cause a film on the surface, I found that out the hard way! Whatever the cause, I still feel your loss. Fortunately, you still have healthy fish that you can enjoy.
