Alright so i have a 12" Black aro of whom i just discovered eats the Hikari food stix, but my question is how many should i feed him? Enough so that he doesnt want any more or should it be a predetermined number?
Just be sensible, arowanas can become gluttons and stuff themselves at every feeding. If you are always feeding until full you may see it grow 2-3" per month. At 12" you should only be feeding once a day. In the case there are other fish in the tank that require more frequent feedings, you may want to feed the aro a little less.
Now that it is accepting food sticks, you should try offering other items too. A varied diet is always a good idea.