help my oscar dieing

[donnas akitas]

iv got a 12" oscar and he looks like he dieing iv give water test and it all right he just layed on side at bottom of tank does anyone know what could be up with him

[OscarFan]

what size tank?
what tank mates?
what are your water parameters?

[donnas akitas]

a pacu a redtail and another big catfish and 2 little plecs he with them all for ages well over a year and his pacu all his life and he in 6ft tank

[OscarFan]

first off pacus and redtail cats need very large tanks.
and what are your water parameters?

[MCHRKiller]

Did you just put the oscar in? They sulk when newly added to the tank, meaning they bleach out lay on the bottom and look like theyre dying. Then a day or so later when theyre more comfortable theyll pop up and act like the own the tank.

[chronic]

How many gallons is your tank. A 6 foot tank can mean alot of different sizes.

You say you tested the water. How?? And what are the readings; ammonia, nitrate and nitrite.

What do you feed him/her?

How often do you change the water?

You need to tell us some more in order to make any assumptions.

[Northernguy]

Some pics as well as your perameters would help us help you!
Have you got a test kit?