Oscar behaving weird

[satan_gal]

Hi Guys...

Need some advise here.
My tiger oscar has been behaving weird for past few weeks.

Signs :

1. Hiding at the water return pipe.
2. lying down at the base of tank at times.
3. Not eating much.
4. Frequent flaring at the albino oscar

Oscar does have a few "holes" in the head area from fighting with the albino and aro but nothing serious, all surface wounds tat din heal properly.

So far I've done WC, added salt, increase the water flow and it's still on off hiding at the base of tank or water return area...

Not normal rite?