Um, lol your arrow will get big enough to eat a monkey, lol I wold say monodactylus sebae will do you for a while as I've seen them with arrows before and they do get huge.
http://www.aquariumphoto.dk/monodactylus_sebae_x.jpg
Keeping the monos happy and looking good becomes difficult with age... as they do prefer salt in their water and need a massive tank. I personally keep them full fresh though. If you are going to get an arrowana minimum your tank needs to be is 3 ft front to back though so the fish can turn around as it approaches adult size. I personally would aim for 4 ft or more though. Monos need a tank of atleast 6 ft in length if not 8 ft, they are speedy devils that will beat themselves to death darting into the glass and decor in smaller tanks. Do a mono school of 5 or larger as mine is 3 and the aggression as they reach sexual maturity is brutal in smaller groups. I already know I need another 3 or so
http://www.aquariumphoto.dk/monodactylus_sebae_x.jpg
Keeping the monos happy and looking good becomes difficult with age... as they do prefer salt in their water and need a massive tank. I personally keep them full fresh though. If you are going to get an arrowana minimum your tank needs to be is 3 ft front to back though so the fish can turn around as it approaches adult size. I personally would aim for 4 ft or more though. Monos need a tank of atleast 6 ft in length if not 8 ft, they are speedy devils that will beat themselves to death darting into the glass and decor in smaller tanks. Do a mono school of 5 or larger as mine is 3 and the aggression as they reach sexual maturity is brutal in smaller groups. I already know I need another 3 or so
