Strange Behavior

Question
I have a young Jack Dempsey cichlid who has been acting strange over the past few days.  He is typically pretty calm other than when he is fed, at that time he usually eats rapidly and darts around the tank.  Occasionally he will appear to be digging in the gravel, but he does that rarely.  

Lately, he has been randomly darting around the tank and knocking things over.  He has even jumped out of the water a few times.  He does it all very quickly, and he must be bumping the bottom too because gravel always flies up.  The behavior is similar to how he acts if he is suddenly disturbed (tank being bumped, someone banging on the glass, etc), but he does it at odd times when there is no obvious disruption to him or the tank.  Occasionally he does it when I walk by, which is also out of character, but he will even do it when I am across the room.  I'm just wondering if there might be an explanation for it?
Thanks!

Answer
Hi Emily,
  Erratic swimming is often one of the first signs of deteriorating water quality. Have you been doing regular weekly water changes?  You should be changing 25% of the water once a week every week. Also, be sure that you are not overfeeding him such that uneaten food is accumulating in the tank.

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