Unless you have a massive tank, don't do it. I raised a black arowana once in a 200 gallon tank, and in retrospect, even that tank wasn't large enough for it. It grew to a size of over 3 feet, and was a constant swimmer. You also need to put into consideration that those fish can be jumpers as well. I had that fish for about 3 years, then one day, it jumped out of the tank... and that in itself is not an easy feat. It had to knock open the wooden hood, and knock off a brick to do it, but it did it. I found it the next morning, stiff as a board on my carpet. That loss turned me off from fish keeping for years.
-Richer