Do you have to change the whitish gravel in an African tank if you go to S. American community tank?

Did you think there was a reason for the whitish gravel? Or is it crushed coral? Either way,changing from one species of fish to another,does not matter as far as the medium in the bottom of the tank is concerned.Your "whitish gravel" is not necessary for African fish. All gravel is fine for fresh water fish.African or South American,it doesn't matter, as long as it has been properly cycled.

Crushed coral is usually used for salt water , it helps balance the PH levels. But can be used in a fresh water set up as well.

no you dont have to its your tank do with it what you wish