My girlfriend was feeding the tank and when she poured in the scoop of food there was a rubber band mixed in. something dime to nickel sized. Before she could grab it, the pacu's raced in and it was gone. a synspillium was also in the area, so it's a possibility too for having eaten it. I've read about fish passing bigger objects than this, like heater clamps, but what should i be on the look out for?