Hi I am thinking of setting up a Piranha tank. The tank is 58in X 22in X 22in inside measurements. I am running an Eheim XL 1200 and a FX6 for filtration. I would like to house a dozen exodon and one Piranha. Is this realistic? If so what suggestions would you have for the Piranha? Also my pH is on the high side at 7.6 is that a problem for Piranha. I just want to get the best knowledge before I begin. If I would be better with a shoal of one species? If so what suggestions would you have. I live close to a dealer that has some real nice fish. Thank you.