aro comms are very common.
in asia, especially where it is cheap to have arownas, people always have many arowanas in one tank.
like cichlids, just slightly more complicated, the more you have the lesser the aggression is focused on one fish.
so, best if you have lots of aros.
3 i hear is really h it and miss.
i hear 5 to 7 is always good. but you need a big tank.
also, odd numbers are supposed to be good.
i have seen videos of even number tnaks, and the aros pair up and fight.
with an odd number, this will mean one is free to swim around and distract others.
how it works APPRENTLY, is that the aros will try to challenge another, then another tries to challenge him, and another tries to challenge the challenger etc and so on, so the aggression breaks down.
people say that there are situations where the arowanas will have one ALPHA, trick is to take out alpha and reintro, re arrange tank.
also, recommendations of putting power heads on the top and mid section of water and make it strong, so this distracts the arowanas so they dont get the change to challenge before they get the powerhead push them. (power heads also help enlarge arowanas size prividing there is enough food!)
also feeding a lot will ensure they are always sedated and settled and not on HUNT mode.
i would not try 2 or 3 or 4 arowanas, i would try 5 and above personally.
I am going to start a aro comm project soon.
3 black, 1 silver and 1 large red.
the red is the most expensive so i will intro the the other arowanas at 35 cms, red is 51cms.
this will ensure the red is top dog.
ill see how it goes.
http://www.youtube.com/watch?v=urK6v8MJkIk
http://www.youtube.com/watch?v=RsA39X1LhP0
here are tanks with multiple asian aros.
the first video, is quite a large tnak.