Accidental pirhana owner

[Heiress]

I have unexpectedly inherited a red belly pirhana. It think it's about 4 years old. I currently have it in a 10 gallon thank, but I understand that it needs a bigger one. So, what size should I buy? I feed him raw fish, is that's enough or does he/she need vegetables or minerals or something?
I always imagined pirhanas living in huges groups in rivers, can one pirhana really be okay buy him self in a tank?

I would really like to keep this fish, and not having to seel him/her so all help is greatly appriciated!

[William]

Hi
even if the age suggest that i should have reached a certain size i would like to know the actuall size of the fish before i give youan answer.

[DiXoN]

yep more info is reqd but as a basic rule for 1 piranha at least a 30g (std 3') would be best.
dixon

[Heiress]

It's about 6 inches.