I plan on getting a 300 gallon pond to put in the basement of the house I'm getting some time this summer. Does anyone have any suggestions as to what kind of pond (preformed, lined,etc.) would be best and whether it would be suitable for a silver arowana. I have a 7" arowana in my 72 gal tank but would like to make him happy as he grows by putting him in the 300 gallon. I also have two other fish that when they max out in size they will need to be in the 300 gallon(fire eel and tire track eel). Any suggestions and help would be very appreciated