How much salt is needed for fresh water pufferfish and bumblebee gobby?

[Nuttawet]

How much salt is needed for fresh water pufferfish and bumblebee gobby?

 

[Essjay]

Fresh water fish should have no salt, except when it is used temporarily to treat a disease. Salt is not good for fresh water fish

There are several species of bumblebee goby. Some are fresh water and some are brackish water.
The fresh water bumblebee gobies do not need salt.
The brackish water bumblebee gobies need marine salt not ordinary salt.

 

[emeraldking]

I also don't get it where you've got that information from that freshwater pufferfish would need salt...
This is not an attack but I'm just curious where you've got that information from. Just like @Essjay has already stated that freshwater fish don't need salt unless it's for a treatment or if it concerns a species that need salt to be able to reproduce (for there are freshwater species that work this way).