put it this way your new 180 if you got it would last less than a year.an arowana is way to big for a 180.you will just hurt the poor fish.most likely the tank is only about 20"-22" wide.an aro would really have to bend.maybe you should sell your aro cats and just get some lil pbass and have a couple in it.aro's get big.im thinking about a 210 here soon in a bout a month and dont know if putting an aro in that is a good idea.it is cruel.save up longer.