Do Fish need minerals added to RO/DI water?

[dr_chee]

I use RO/DI water in my fish only tank and my reef tank. Does anyone know whether I need to dose the water with minerals to keep the fish happy in the fish only tank? Right now I just add pH buffer. Thanks.

[justinl]

nope

fish don't use up calcium or any other "minerals" nearly as fast as a reef tank. As long as your salt is decent quality and you do regular water changes, everything in your tank will get all the stuff it needs.

if you want you can do a few tests (calcium, etc..) to be sure.