oscar lying on the bottom

Question
I have a baby tiger oscar that was doing just the day before and today it is just lying on the bottom of the tank breathing heavily. It is a 40 gallon tank with only 1 fish in it. The tank water is all new the water is about 1 week old. The temperature is around 24 degrees celsuis. Am I overfeeding? I feed everyday is that ok? Please help thanks.

Answer
Hi Sam,
You must quickly try to find a place to house your Oscar or he will die.  A tank needs time to cycle, almost 4 weeks.  Right now your water chemistry isn't right.  When a tank has cycled, this means no ammonia, no nitrites, and nitrites should be low.
To cycle your tank, buy an old sponge that fits your filter, and let your water run through this old sponge for 4 weeks, adding water that will evaporate, then check your water chemistry.  Ammonia must be zero, nitrites zero, and nitrates must be low.  Right now you water chemistry is way off.  You must have ammonia, and nitrites in your water.  This is poison to fish, and they are the number one killer of fish.  
A sponge is good for a very long time, until it is old, ragged, and falling apart.  Once you have the right water chemistry, always rinse your sponge in water that you have removed from the tank.  Tap water will kill the good bacteria there is in the sponge.
Foe now, bring him back to the pet store, and ask them to house him for you until your water chemistry is right.  He will die, if you don't find him a cycled tank.
I'm sorry, but there is nothing else you can do for him at this time.  Fish need good bacteria in order to survive, and this means a cycled tank.
Lynda