I currently have a 120 gallon tank that houses 2 oscars, a pleco and a shovelnose catfish, I want to start a pirahna tank and I am going to, once the fish in the 120 are gone. The question is: How many pirahnas can I fit in there?
"I would recommend only keeping 2 piranhas per 60gallon tank (depending on species), and at least 20gallons extra for each additional fish. It is possible to add more fish, but if you want your piranhas to live happy and show natural behavior, this is the best formula, in my experience." http://www.geocities.com/heartland/prairie...5962/Start.html
the piranhas will not attack your hand they are just as scared of your hand as you are to them so dont worry but just dont chase them around with your hand they could bite it out of defending them selfs
BTW in a 60 gal tank you could have 3 in there with no problems and will still show natual behavior also the 20gal per p is only up to 85 gal after that it depends on the tank