emergency with black belt cichlid, please help fast if you can

Question
I have about a year old black belt cichlid. She has always been very calm and healthy, never any problems with her. Keep a clean tank, vacuum about one a week. Today she just went absolutely crazy when I tried to vacuum. She was swimming as fast as she could around the tank slamming herself into everything! The top, the sides everything in the middle! This went on for about ten seconds,but was enough to cause alot of damage. She is pretty beat up and is gasping and in her hiding spot belly up :( I don't know what to do. I'm in tears, I really don't want to lose her. Please help if you can.

Answer
Hi Katie,
 I am very sorry to hear what has happened.  I have seen this sort of thing but very rarely.  It can sometimes be caused by deteriorating water conditions.  As the water conditions get worse, the ammonia and other nitrogen products make the fish more and more "skittish".  That would be my guess, but that does not fit with you saying that you do weekly water changes.  When you do the water changes, do you remove about 25% of the water?  

 Also, when you add water back in, could it have chlorine in it?  

-- Ron C.
  rcoleman@cichlidresearch.com
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