dying oscar

Question
My 2yr old daughter has learned to climb and over fed our fish on 11-23 and now my albino oscar is loosing some of his scales and his side fins have lost the skin in between them my wife noticed the overfeeding 11-23 shortly after our daughter had fed the brand new large container that is now empty, my wife changed almost all of the water that day,we have checked water conditions and everything good. Is there anything we can do for our fish he is now floating on the bottom and barely breathing earlier today he was looking better but has now gone downhill.

Answer
Hi Jason,
 Hmm... so, let me understand this.  Your daughter fed a whole can of fish food to the oscar, right?  Then your wife changed almost all the water... and now the fish looks very bad.

 There's good news and bad news.  The good news is that feeding a whole can of fish food won't in itself hurt the fish. The bigger problem is that it clouds the water.  That takes a certain amount of time, namely at least a day. But you said that your wife noticed this right away? (Could it actually have happened a day earlier?)  The bad news is that changing that much water may have been more detrimental than the fish food.  I suspect what has happened is that the tank chemistry is going haywire.  When you said you checked the water conditions, what parameters did you check, i.e. did you look at ammonia and/or chloramine?

Also, how large a tank is it?

Do you use city water for the tank and do you have to treat it prior to putting it in the tank?

Whatever you do, don't put a bunch more chemicals in there. The only thing I would consider adding is something like Amquel to deal with ammonia and chloramine if that is in your incoming water.  

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