Fast enough that if it wants to, and your hand is in the tank, it will take a chunk out of you...seriously.
I've been bitten so fast it didn't even hurt...at first.
I trded them to a guy with a 400g and a school of RBPs and he said he has had them shoot three feet into the air and land out of the tank to flop on the floor...and yes, they will bite you outside the tank as well.
Piranha are cool.
ok I already know they go "fast" lol 25 mph sounds about right and mine don't jump you hear them zoom across the tank though messing up my gravel though heh
Lol. I like that reply. Yes, I believe piranha can really move fast at a short distance. I have been a piranha owner for a long time and I experienced piranha to move very quick. Be careful and have a lot of respect for piranha.
they arent so much fast as they are quick. yes they can swim the length of my 6ft tank in the blink of an eye, but i dont think they can keep up that speed for any real distance. they arent swordfish or anything.