quarterback13

I have a columbian shark I introduced to the tank a week ago and yesterday I added 2 bala sharks. All 3 sharks are about 2 inches in length. The columbian was doing very well until today. I found him lying in a plant and breathing heavey . I'm sure he is dying. Would the balas be responsible?

mathas

It's not likely the balas had much to do with it, unless they brought a disease with them. It might be helpful to know your water parameters (ammonia, nitrite, nitrate), though.

One potential cause of problems is that columbian sharks require brackish water when young, and an increased salinity as they age. See this thread: salt

Shawnie

as well as what mathas said, the tank is new and probably ammonia is high...this link will help alot as well as mathas advice

http://www.fishlore.com/NitrogenCycle.htm

Jonah

And not only that but a Columbian and 2 balas are going to out grow a 72gal tank very soon.

The Columbian will need full salt water by the time it matures and the Balas are more freshwater fish so they really are incompatible tank mates regadless of the size issues