In my experience Acaras are way less aggressive than JDs. As Juvies they'd be good but once the JD is full grown at 10" and the Acara is only 6", the Acara's existence will be subject to the disposition of the JD. I you had a pair of JDs, forget it. On the other hand, A bonded pair of Acaras with a Single JD may work. Just my 2 cents.