Im a piranha keeper and am looking at trying out rays. I want to know if a single ray could be kept in a standard 75 for a yr or so? Im just going to try it out before i go to college and see how it was. I was thinking maybe i could find a small one about the time college rolled around i could rehome him/her. Any advice? If you all say this is a bad idea im fine and i can continue piranha keeping. Thanks for your help. Also my fliltration is an emperror 400 and an eheim 2217 cannister