Arowana to small for prdetor tank

Hi,

I have a 5 month old Silver Arowana. It is currently in a smallish tank with a couple of eels and louches.

I have a bigger tank with predetory fish like two oscars, a Clown Knife Fish a tire Track eel etc. I wanted to transfere the Arowana to that tank because I thought its large enough but the Oscar imediately attacked it and I removed it out of fear that it may be killed. The Oscar is about 25cm long and the Arowana 20cm. Still a young one.
How big do you guys suggest must the Arowana be before I put it back with the Oscar etc. Incidently, I have two Blue Texas's also in that tank and they are about 13cm long but the Oscar and Knife ignor them generally. They are in the tank since the beginnig and may be used to each other?

Thanks for great forum. I awaits your replies.

Regards,

The pred tank is 55gal.
How long will it take to grow to 15" do you think. I am feeding it mealworms and bloodworms. It did't like arowana pellets.

Thanks for response.

regards

Thank you all for the advice. I will invest in larger predator tank and transfer the Aro to the 55g till large enough to transfer to new big tank.

Thank you for positive response.

Regards

In normal circumstances with enough tank space etc. How long, in your opinion, will a Silver Arowana take to reach 15-17inch? As I have mentioned earlier, mine is now about 4-5 months old and is now 9-10inch long.

Regards