THanks bro. S my arowana is taking only pellets. He is not taken prawn while i gave to him. Here my arowana come and get the pellets by pellets by standing near of our hands.. After his stomach fill he started to move awaay from the hands and started to play in the air bubbles.The 5ft tank can work... Let's guess say it's a minimum size
Is your aro trained on pellets? You can also consider baby frogs or mealworms at this moment if it does not eat pellets
With a good filtration, an aro and oscar is not a problem... Good to have a fish competing with the aro for food, many keepers says it helps with the aro appetite