Yo bro! It's looks bad when Oscar fish bullies arowans , but this is what I think , I too have an arowan and 2 Oscars in my tank with a giant gourami and my arowan also keeps getting bullied in the tank , it's mostly because Oscars are dominating fish and nothing can be done but to just let them grow together , even though both fishes grow fast arowan will keep growing even after Oscar reaches max , my arowan also gets hurt by the Oscars but u have be patient with them don't try to get the Oscar under control it will increase the aggression. Observe is the arowan is eating regularly, feed it 4 times a day after every 4 hours , if it's eating well then no problem yo just wait patiently for the fishes to grow , keep using api Melafix and Pimafix and add Cattapa leaves extract without boiling the leaves just let the leaves sit in the water for 24 hours and then pour only the water in the tank this will reduse the stress and its also very good for your fishes, the arowan will be able to remain healthy and the Oscars is rarely attack other fishes , change 30 to 40 percent of water every weak and add the api medicine's and the leaf extract , keep doing this regularly ,also set the temperature to 26 degree celsius. I hope this helps your arowan , I'm doing the same bro coz I too don't want to seperate the fishes. Happy fish keeping!
RD. Would tell you only to feed them nori because land plants are unhealthy. In the wild, they eat plants and steal good from other fish. that is why they are so far and face such strong jaws.
