gold fish paralysis

Question
QUESTION: my golfish was favoring his right side so i changed the water in the tank... in the process of cleaning the tank he died, while the other remained living though wheni put her back in the tank, she sank to the bottom. she isnt moving but she is "breathing". could she be in shock about her tank mate?

ANSWER: Hi Lindsay,
  She could be in shock from the water change, but not from the loss of her tank mate.  
When cleaning a fish tank, in general, you shouldn't change more than about 50% of the water at one time.  More than that can be shocking to a fish.  Also, be sure that you do not use any detergents or soaps or lotions of any kind anywhere near a fish tank.  That includes on your hands. These things break down the natural protective slime layer that covers a fish's body.

-- Ron C.
  rcoleman@cichlidresearch.com
  Cichlid Research Home Page <http://cichlidresearch.com>


---------- FOLLOW-UP ----------

QUESTION: What could have caused the other fish to die?  ( trying to make sure It doesn't happen to the other fish)

Answer
Hi Lindsay,
The most common problems would be moving the fish between two containers of water where the water is very different in temperature in the two containers.  Other common problems are the presence of chlorine in the water (most city water has this and it must be removed before you put fish in it).
As I mentioned previously, soaps, detergents or bleach can all kill fish.  

-- Ron C.
  rcoleman@cichlidresearch.com
  Cichlid Research Home Page <http://cichlidresearch.com>