Oscar behavioral symptoms

Question
I have three oscars in a 75 gallon tank, two red tiger oscars and one albino.  I've had them for about eight months now.  The red tigers are eight inches long approximately, and the albino is five inches.  They were doing fine, until I noticed in the past month some strange behavior; I notice that they swim on their sides quite freqently. In fact, when I came home two nights ago from being out of town for two days, I exerienced a fright when I saw one of them hanging motionless by the surface of the water.  So immediately, I did a half water change, sucked up debris in the gravel with my vacuum, and cleaned our Fluval filter.  I added ammonia and algae remover immediately afterwards. They seemed better afterwards, but they still swim on their sides occasionally, and sometimes they seem to experience seizures in different parts of their bodies, primarily the tail fin.

The research I've done on this behavior says that this would be a behavioral symptomatic response to slow chemical poisoning.  I don't know what else to do aside from keeping the water clean.  Did I do too much at one time?

Answer
Hi Christina,
 No you didn't do too much.  Oscars can take large water changes and in fact, it is good for them because they pollute the water so much.

 Could it be that your tank is getting too warm with the hot weather all across the nation?   Be sure that you have a airstone that is working well these days.

-- Ron
  rcoleman@cichlidresearch.com
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