i have 8 red piranahs in a 120 gallon. tank they are about 2 and a half to 3 inches in lenth i also have a common plec in there to hes about 11 inches in lenth.today i threw in a king prawn and the piranahs started feedin as soon as it hit the water then as soon as it hit the gravel the plec started fighting off the piranahs and started sucking on it!! i feed the plec a wafer every night b4 i go to bed and he eats them every single time plus i thought these commons were just an algie eater!! should i get rid of my plec b4 the red bellies turn!! thnx for readin