No, it really doesn't. Many people think though, that salt is something that goldfish need, but it's only specific kinds of fish that need slightly salty/brackish water

It also slows down the filter bacteria so that the ammonia is broken down slower while having salt in the tank.
I recently had to add some to my 83 gallon, and after that I had nitrite spikes and one of my fish got badly sick :/ Only to be used when treating parasites, fungus or helping the fish heal visible wounds
