I watched a few videos on piranha feeding. I'm seriously considering dropping my arowana idea and going for piranha in my 150 gallon instead, regardless that I absolutely love arowana. I love piranha aswell. I can make an excellent home for any type of piranha that will fit in there. I would rather a school of more than 10 in there though.. What type would you recommend? I don't know if I'm into the redbellies as much as a more vicious type. I want mean ones. Any suggestions?