I have used the inexpensive Index pools for large fish, or you could also use one of the Rubbermid stock tanks ( I would suggest the 300 gallon for your arowana) and because its a jumper, using some kind of cover netting wouldn't be a bad idea).
Below is the Intex @ 400 gal type, I used it to overwinter pond fish
More durable, are the Rubbermaid stock tanks, available at some Home improvement centers like Home Depot
As you can see, I sunk mine into the ground, like a real pond, and it is tough enough to take freezing and thawing.
the Index would fall apart.
I've also tried the Bestway brand, cheaper, less reliable.
Below is their almost 1,000 gallon unit
Below is the Intex @ 400 gal type, I used it to overwinter pond fish
More durable, are the Rubbermaid stock tanks, available at some Home improvement centers like Home Depot
As you can see, I sunk mine into the ground, like a real pond, and it is tough enough to take freezing and thawing.
the Index would fall apart.
I've also tried the Bestway brand, cheaper, less reliable.
Below is their almost 1,000 gallon unit