odd behavior?

Question
Hi I was hoping you could help me figure out why my fish were acting so strange?  I have a small tank of orange guppies [i believe] and all of them seem to staying at the bottom of the tank with the pebbles.  When they are not there, they are still pretty low in the tank and just seem to wiggle/swim in place.  I was wondering if it is because something is wrong, if they`re sick, or if they are mourning a fish that we lost two days ago. :(  please help! it is much appreciated!!
--stephanie :)

Answer
Hi Stephanie,
 Have you been doing regular weekly water changes?  You should be changing 25% of the water once a week, every week to keep your fish happy and healthy.  

 Also, do you have a heater in the tank?  If not, you need one.

-- Ron
  rcoleman@cichlidresearch.com
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