My scalare angel is putting on some girth -- it looks fat! The marble veiltale angel in the same tank is still 'thin' as it should be. The fat fish has looked this way for about two weeks and was still active, but today did not eat when I fed the fish and its breathing seems laboured. My guess is the fat fish is going to die. Any idea what this is?
Temperature 80 degrees F; ph neutral. I don't have test kits for ammonia or nitrite but I change water weekly and the rest of the inhabitants are doing fine. 46 gallon tank set up in August, no fish loss to date.