i have a 90 gallon with 1 oscar 1 ebjd 1 gold sev 3 loaches and 1 pleco. when i walked into the store today to ask for advice about my oscar being very aggresive toward my sev he said that my tank was too small and there wasnt much you can do. he recommended that i found another home for the oscar? which i dont mind doing really since my sev was 23 dollars i just am not sure what to do. any suggestions?

If any fish is being constantly picked on it worth thinking about re homing it. space (tank size) plays a part in how some fish get on and if the Oscar wants more space the small fish usually loose out. how long they been together?

rehoming may be an option, but i live by my signature.
I'd get an upgrade to a bigger tank and keep the Oscar, though.
But that's a personal choice and i do not know if upgrading's even an option.

Namaste, have you tried any Dithers? maybe try a school of SDs. I know they recently calmed down an overly aggressive convict i have, yet its a stretch they may do the same for your O. BIGGER TANK if you can Best of luck my friend, all is as it must be

If 2 fish are fighting you can try rearranging the tank. If that dont help then put a divider in and wait for a week or so and then put the aggressive one in the other side. If the aggression continues then you will have to rehome one fish. If i were you i would rehome the agrressor