What they need is LOVE. Thy are like any dog or cat or any pet. They need your time and your money to survive. Other than that, basic need is clean water, good healthy diet, nice cover lid with a monster tank to roam in.
it needs a person dedicated to provide whats necessary for a monster fish. of course every person thinks they can handle a arowana cuz its "only a fish" right? but you will soon realize over time ur fish is more then just a fish to you and will need ur passion to provide him with proper care.