I read a few things about white stringy poop. That the fish is fine and was just pooping the remainder of what was left in the digestive tack... and that it was a tape worm. So what one is it. The digestive track thing seems a bit far fetched, and considering i feed them pellets twice a day unlikely that he doesnt get any. So if its tape worms would this spread to my other fish and will it go away on its own? Is it life threatening? I would quarantine him but it is very hard to catch a 2" fish in a 225gal tank with a lot of rock structure to hide in. If it wont go away what do i use to treat it? will the treatment hurt any of the unaffected piranha? How much is it gonna cost to treat over 200 gallons?