Help my arowana’s got into a fight

[Bjohn39]

I have had these two 4 inch arowanas together for about a month and suddenly one almost killed the other the smaller of the two beat up the larger one and he’s on the bottom of the breeder box so I could seperate them but he is badly beaten and is breathing shallow what should I do

 

[Midwater]

Separate them!

Never keep two.

One or many (if you have an enormous tank).

 

[Irecruitfish]

I have had these two 4 inch arowanas together for about a month and suddenly one almost killed the other the smaller of the two beat up the larger one and he’s on the bottom of the breeder box so I could seperate them but he is badly beaten and is breathing shallow what should I do

Same thing about to me. 11" all of a sudden beat up a 12". Had to re-home the 12". I also didn't have many fish to distract them.