pacu problems

Question
My pacu, Ted, has been swimming full speed into the side of my 120 gallon tank and has knocked out his teeth on his right side and also has a laceration medial to the right 'nostral'. Is this common behavior? How can I stop it if it is not, or is Ted just really dumb? I am really worried he is going to get severely hurt soon, he has broken on heater doing this and it didn't phase him. What should i do? He is still small too...

Answer
Hi Erich,
 The most common cause of this sort of behavior is deteriorating water conditions. As the water gets worse and worse, the fish does more of these "mad dashes" around the tank.  Have you been doing regular weekly partial water changes?  You should be changing 25% of the water per week, though in a large tank like that, you can probably get away with a little less, except if you feed the tank heavily.   

-- Ron
  rcoleman@cichlidresearch.com
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