yeah it's true you can keep any fish w/ a piranha, but its not recommended. P's can and will eat any other fish in the tank. Exodons are nice fish and definitely not worth losing any or all in a p tank. If you want exodons, get them thier own tank you wont regret it.
I have never been able to keep any type of fish with piranha for very long, sooner or later they ate everything including plecos that were considerably larger than they were.
I've kept 10 exos with my juvi reds for about a year, kept the ps well fed but all of a sudden the ps just took out all of the exos in a single night. I've even tried plecos but they ended up gettin eaten. Nothing can live with ps. There are some members that can personally say otherwise
when trying to find something that will stay with the p's for a long period of time u have to find something that is really fast or something that is to small for them to pay attention to......p's are lighting fast so its hard to find something that can get away from them
my girlfriend has a blue crayfish about 5" this attacks the rbp whenever we put food in if they dont get it before it hits the bottom the crayfish gets it and the piranhas have to wait untill its finished its the most aggresive fish i have ever seen you could say it bullies the piranhas they are only about 2.4-3" this may change as they grow but right now the crayfish rules the tank
Years ago I had 12 small Red Bellies in a 55 gallon with a pictus cat. 9 months and it still lived. I don't know how he did it, but he did. After that I sold them and got Sone nice
central am-cichlids.
exodons are very fast and are pretty aggressive as well. if you had a big enough tank with big enough P's you could most definitely keep a crew of exodons as part of the clean up crew. dont be surprised if some of the P's get their fins nipped either or if you lose an ex once in a while. with P's stuff dies. as long as the ex's have a set up that offers them some protection and room to run they WILL survive. if the p's are started out small with the ex's you will more than likely lose the ex's to them. on the other hand if the p's are in the 6 to 9" range and are well fed you shouldnt have a problem. ive had more trouble keeping p's with larger fish, most smaller tankmates are left alone once the p's put on size. that is until you miss a feeding time then they make their own dinner