Is it necessary to use aquarium salt in a tank before your fish is ill?

[McLizardman]

Hi, I heard that it is a good idea to use aquarium salt in your betta tank, but is it necessary to use before the betta gets ill? Should it be added during water changes? Thanks so much for the help!

EDIT: Just realized this may be in the wrong forum topic. My fault. If there are moderators you could move this if possible? Sorry.

[SmokeNLark]

Salt is a decision that's up to you. Some people use it as a preventative.

Personally, I do not like using it unless my fish is sick. Bettas are freshwater fish, not brackish or salt water. Also, when salt is always in the tank, they will build up a tolerance to it and it will be less effective when your fish does get sick. Also, constant use of salt can cause the kidneys to stop functioning properly.

[TheCrysCat]

Basically what SmokeNLark said. I wouldn't recommend it, because it'll just be one more thing added to the water and your fish will build up a tolerance to it if you ever have to use it. The fish aren't meant to live in salt water long-term, which is why all of the treatments say to discontinue after 10 days.