And there is the added layer of difficulty introduced by the fact that this is a 15 gallon tank containing not one, not two, but three extremely fast-growing fish which will all eat food and produce ammonia at astonishing rates. This "community" will require a huge tank upgrade...not next year, or in a few months, but literally within a few weeks.
No, I am not trying to discourage a new aquarist, contrary to the inevitable comments; I am simply pointing out the folly of unplanned impulsive purchases of monster fish, especially when there is insufficient housing available for them. Encouraging that behaviour doesn't do anyone any favours...most especially the fish.
Personally, I think the Arowana and Oscar will get along wonderfully together...inside the Red-tail...soon...assuming that massive water changes are done frequently enough to keep them healthy for the month or two it will take the cat to grow large enough to hunt them down in two square feet of real estate. The Arowana will disappear first, since the Oscar will out-compete it for the lion's share of the food. But the required overfeeding that will be done to allow the Aro to get anything to eat will explode the cat at a size that must be seen to be believed, and that's the beginning of the end.
