Jer

I have a black fin (colombian) shark and a bala shark in a 20 gallon freshwater tank. I know that the tank is too small. However, are they compatible? For how long?

KittieKat

i have the same combo in a 125... one columbian and 4 balas..... they are both rather peaceful fish. the catfish is a bottom dweller and the balas are mid to upper tank swimmers so they hardly cross paths. they are fine together because the columbian can grow up to 24" (2 feet!) yet stay at about 14" or less in a tank and theoretically, bala sharks grow to 14 inches but more often end up at 10-12". so the balas really are never small enough to fit in the catfish's mouth.

as the catfish ages it needs to be brought to brackish water and then to full strength saltwater. in the wild they slowly work their way to the ocean as they age so they need the same to happen in a tank. if this doesnt happen they become weakened, develop bizarre "rashes", and it can be lethal.

balas like alittle salt and adjust to nearly any water conditions so they can live in brackish conditions but will need to be removed when the time comes to convert to saltwater for the catfish

Jer

Thanks for your reply! I like the cat fish but I'm not sure I'm up for the transition from fresh water to brackish to salt. Maybe I'll see if thefolks at the fish store will let me exchange the colombian for another bala.