red devil fish

Question
I have a red devil that is 12 years old.  He has been acting strange lately by staying in the corner, then staying vertical with his head down.  Now he is turning upside down.  I'm not sure this is good for him.  He has never acted like this before. What should i do, if anything?

Answer
Hi Teresa,
Make sure that your water chemistry is safe, free of ammonia, and nitrates.
You could try feeding him a cooked frozen peas.  Remove the first layer, and cut into small pieces.  He may have swim bladder disease, and this would help to clean out his system.  Swim Bladder is usually caused by overfeeding, and constipation.  Seeing has you have had him for 12 years you must have taken good care of him.  You could also check that the temperature of his water hasn't gone up...sometimes the heater breaks and goes up without warning...
I would also like to mention that the Devil Fish usually live up to 11 years when well treated, so congratulations, you really took good care of him!
I hope that he comes back to his normal self, and if he gives any other sign of distress, please write me again.
Lynda