He basically said getting one Rope FIsh wont work, it will become stressed out as well, seeing as it is a schooling fish. you need at least 3 or 4 (imo). I want some too, but am holding off untill i have both the room and time dedicated to them.
BTW, how did the bala jump out? did you leave the lid open, or are there a lot of open gaps? If there are, fix them, then think about Rope Fish. They are jumpers, and will sim into the filter intake if given the chance, and will jump out if given the chance.