Are you asking how you should set up an Arowana tank? If so, leave the top 1/2 to 1/3 open for swimming area, other than that, it's really personal preference. Some people like bare bottom tanks for their Aro's, some like more of a habitat set up. I have mine with some smaller driftwood/plant decorations on sand. It's really just preference, after you allow for their natural swimming area. They'll "pace" back and forth in thier tank most times.