Hi I'm new here! I've had my 2 Oscars for almost 2 years now.

They'd fight every once in a while but nothing major and now they've outgrown their old tank so I got a new larger tank for them.

Then started getting some problems

1 of my Oscars (for simplicity I'll name them Orange and Black), Orange, has been bullying Black. Black now just hides behind 1 of my decorations in the corner of the tank all day and night. Whenever Black tries to come out, Orange would charge and force Black into the corner.

I figured that I could get other fish in the tank, since my new tank is much bigger I figured I could put more fish in it instead of having just 2 fish. This way Orange might bully the other fish instead of Black.

In the beginning I had 8 Oscars, 4 white, 4 black/orange. They basically killed each other off till there was just 2 left. So I found this site and used it as a guide to see what I could mix with my Oscars, didn't want them to kill off any other fish (I mean they even killed my sucker fish (plecos I think they're called).

So I figured that Catfish were an ok tank mate. They only 2 types of catfish that I managed to find here are Red Tail Catfish and the Patin Catfish. The red tail is kinda too big so I opted for 2 small Patins, which are almost as long as my Oscars.

Well it worked, sorta... Orange didn't attack Black as much but would chase my patins all over the tank, the Patins are pretty fast so I didn't worry too much. That was day 1. Day 2: 1 Patin died, he was chewed up pretty badly, bleeding and everything...the other Patin barely survived, he had bite marks, torn fins and was bleeding in a few places. I've moved my surviving Patin into my old tank. And now Orange is back to bullying Black, and my Patin is slowly recovering.

What should I do?!! Should I just put Orange in a separate tank? And hope Black is not as crazy aggressive and have it with a bunch of Patins in my new tank?

Here's a pic of when they were all in the same tank.

Black in the yellow circle, Orange in the red circle and 1 of my Patins in the green circle.

What is the size of that tank? They say 55gal should be the minimum for one adult oscar. Though most prefer 75gal. In my understanding, you just recently moved them to that new tank am I right? If that is so, it may be since they were introduced to a new tank, they are having territorial issues that's why they fight more often now. You could try rearranging the decors and see if it would decrease their aggression. It's pretty normal that they fight but if one of them is being injured severely, you may want to separate them. If your tank is 100gal+, you can install a divider. Though it may not be an eye pleaser, it's an option. Or you could just simply rehome the other one..

I have approx 60 gallon tank I think, I'll make a proper measurement later on, I'm not used to using inches.

They weren't fighting as much in a 20 gallon tank. And they've been in the 60 gallon tank for a month now, with Black still just hiding in the corner. I've set it up so that Black can hide better without being attacked but it's still reluctant to swim about the tank as much as when I first moved them to it, they were fine for about the 1st week, swimming around the whole tank together.

*sigh* it's just sad that I can't put other fish in the tank without fear they'd be killed. It's such a big tank just for 2 fish (well just 1 really since the other 1 just hides in the corner all day)

20gal tank is not for oscars. A 1-2 inch juvenile oscar can grow up to six inches within six months. That's the stage where they grow the fastest.

60gal tank is too small for two Oscars. As they've said, 55-75gallons is only for ONE oscar. Since you have two, you have to have 100gal for them. Small space means more aggression. I'm afraid their fights will continue and may lead to some injuries for the inferior oscar. You have to rehome one of them or upgrade to a bigger tank..

BTW, What's the current size of your oscars?

x2 urgent upgrade or re-home is nessersary if yr oscars are large, if there juviniles u may be ok depending on their exact size.

but if adults u need to sort that out or prepare for the worst, at the end of the day there yr fish but its their health at risk matey

btw welcome to the site

Thanks for the welcome

I've double checked my tank measurements and ya it's about 60 gallons.

So I'm going to have to separate them I guess, Orange is gonna be all alone now I suppose since I don't really want to risk putting in other fish if it's just gonna attack it all the time.

I'll try other fish with Black, since it seems a lot calmer and not aggressive at all.

My other Patin catfish succumbed to it's wounds today

Orange is about 7-8inches, and Black is about 6-7inches.

Your O's should be ALOT bigger. Do you have a test kit? Have you tried lower the temp in the tank. I keep my tank at about 76.5 F. The main reasons for aggression is food and space. How much and what do you feed your O's and how often?

Just to update, I've moved Orange into a tank of its own and I think it's just better that way.

Black is fine now, and swims about, and I've added 2 Patin Catfish and they seem to be ok. Black would chase them a little if they disturbed it, but not like Orange who actually attacked the Patin till they died!

I can't seem to find much info on Patin Catfish though...

nice to know that you have keep both of them. nice move.

i had surf ptin catfish and surprised to find out it is ID shark or pangasius

nice thanks for the help! How long before yours got to be that big?



Mine are tiny in comparo!

they are about 32 months old, the white is 25 inches long now while the black
is about 24 inches long. i have to minimized the food to lessen the growth..
they are becoming huge and very active.... giving no time for the oscar to
keep on fighting