Whilst doing my daily routine of checking the tanks, I have noticed that one of the Cory Catfish has what looks to be red blotch disease. All other inhabitants of the tank look to be just fine, including the other 4 corydoras.
The only noticeable difference is a few plants have melted back a little. I did a water test to find that ammonia is pretty much 0, nitrates are a little higher at 20ppm (I water change every Sunday), but nitrites were at 0.25 (Usually 0 of course)
I recently treated the tank with hydrogen peroxide to battle some BBA (this has worked well). I also raised the temp of the tank by 2 degree Celsius about a week ago. Has the treatment caused the increase in Nitrites, or this red blotch disease?
I have a 2nd tank that I can quarantine the wee fella in for now, is this condition contagious?, and what is the best treatment?
Thanks, Andy