A lot of swimming space is necessary. Decorate with rock work, bogwood/driftwood and sturdy plants. An agitated Asian Arowana may uproot plants with poor root systems.
6 or more juveniles can be kept together, but 10 or more is better. The same with adults, but this is a gamble as some adults do not tolerate others of their own kind well. Beside keeping them in schools they should be kept with peaceful to moderately aggressive fish that cannot be eaten and that will not harass the Arowana.