My oscar fish has been fighting with another fish my sister got, its a sucky fish (dont know name, but only that its got a red tiger patternd skin, a french mustash and sucks the tank clean) anyway they've been fighting and now the sucky fish is scared to bits because Phillis (our oscar fish) has been attacking him and ripped off the sucky fish's mustash and now he just hides under the filter. but now my oscar fish is showing really odd symptoms. i fed him his normal amount and he had only a few bites and then after about 1-2hours he started to swim on the ground but not upright, he's kinda lopsided, like at 60*. and then he just jetted randomly into the side of the tank. I dont really know how old phillis is but my gues is about 3-5mounths... ish

can someone please tell me whats up with him and whats the best way to solve it.
sorry i couldnt give much information about it

Firstly, welcome to our community

How big is your tank? What type of filtering have you got?It is not uncommon for there to be aggression amongst fish. I think the best thing you can do is re-home the other fish, I suspect it is actually a pleco.

Have you tested your water for ammonia, nitrite, nitrates and PH? Is your Oscar breathing heavily at all? Anyway, you must test your water as soon as possible and get back to us with the results. I'm not sure why your fish is doing this, but we do need to know what the conditions are.

He seems to be fine now, we are thinking of moving the other fish but tanks do cost alot, and if we did move him we'd proberly get a few more fish. But my friend came over and quickly solved the problem we were having with phillis, something about not cleaning the tank when we put in the other fish, and the tank had to be cleand out again.
There is still some conflict between the fish but... fish will be fish.

our tank is 220 litres
ammonia and nitrate lvls are at 0 (yay)
our filter is Fluval 2 - and i clean the spunge thing every 2weeks

Phillis isnt breathing heavily at all, he is just being him and coming up to the edge of the tank to great me (even more yay)

Cleaning your filter every 2 weeks is too often. i would go with every 6 weeks or so

Saying that a Fluval 2 is not big enough for your tank. You need to buy an external filter. A fluval 405 (external cannister) would do the trick

ok, will do

thanks