Oscar Isn't Acting Normal

[OP4500]

I have a young red oscar, he's about 5" long living in a 15 gal aquarium with a peacock cichlid. Lately he has been spending a lot of time laying on his side in a pit at the bottom of the tank. Looks like hes dead, then he will just randomly start swimming around like normal. He doesn't seem to be eating as much, fed him around 10-15 medium cichlid pellets per day, lately he eats about 5. My filter hasn't been working well for the last couple weeks and quit completely yesterday so I replaced it with a 250gph filter and it seems to have improved things. So is he sick or just acting weird? This is my first oscar and he been doing this for 2 weeks, all the other fish I've had that did that ended up dead within 2 days. 

 

[star4]

First off your tank is way too small for an oscar, even a 5" one as they grow really fast. He is most likely really stressed at being in such a small space.

 

[sawickib]

Tank is WAY to small for a oscar and the other cichlid, what are the water parameters of the tank? How often do you do water changes and how much? When you got the new filter did you keep your old filter media?

 

[fishlover101]

you need a 55g min for an Oscar, or so ive heard. this is probably why this is happening

 

[sawickib]

Oscars need at least a 75 gallon i would suggest.

 

[Ninjouzata]

to TFF!
 
As has been said, your tank is too small for the oscar. This may be stressing him out and depending on if you cycled the tank or not the water quality could be affecting him too.
I'd recommend upgrading to a 75g ASAP. Am not sure what size tank the peacock cichlid needs but it surely needs something bigger than this as well.
 
Can you give your water parameters? (ph, ammonia, nitrite, nitrate)
How long has the tank been set up? Did you cycle it? If so, how? What sort of test kit do you have? What is your water change schedule?
 
When did you get him? How long has he been acting this way? Can you get a picture?
 
When you switched to the new filter, did you move the filter media over?
 
Please keep in mind we are not trying to attack you and just want to help your fish. Sorry for all the questions