my fish died, and Im not sure why.

Question
What does it mean when your fish's eyes become foggy? They also started to look very sickly, with heavy breathing. Then the fish died. What is going on with my tank???? thanks, Alex.

Answer
Hi Alexandra,
Sorry to hear that. Were there any other signs? Discoloration, swelling, growths, redness or fraying of fins, loss of appetite, etc.?  What was the water quality like the last time you tested? The cloudy eyes and labored breathing are signs of many fish ailments/diseases, as well as a sign of toxic response to ammonia. So without anything to go on other than that its hard for me to say exactly. Could have been a bacterial infection, velvet, ich, poor nutrition... numerous others. Your best bet is to test the water and record all data. Make sure it wasn't a water quality issue. Try and remember any odd behaviors you might have seen(that would be a great help to me in id). I would do a 50% water change, and get ready to get back on the horse. Im sorry I cant be more specific. Get back to me with any of the info I requested and I'll be glad to help. Dont give up.