Salt as a treatment

Question
Hi David. I was doing research on using salt as a treatment for different ailments in freshwater fish and I'm coming across conflicting messages. I was wondering if you could give me some insight on what the different types of salt are used for (epsom salt, aquarium salt, table salt). Also, is iodized salt harmful to fish?
Thank you,
Theresa

Answer
Hello Theresa:  The only salt you should ever use in your freshwater aquarium is aquarium salt... and for saltwater use only salt this is labeled for saltwater aquarium.  There are not strict rules about what the definition of salt is... whether that is Epsom salt or table salt.  I iodized salt can be harmful to fish... especially salt water fish... this is one of the reason why people use DI water ( deionized) or RO water (reverse osmosis)... both of theses types of water remove metals from fish... Copper for example is a toxin that kills off parasites and invertebrates and at higher doses... fish.  So please just use aquarium salt.  Salt is also not the end all for treating fish... The difference between freshwater salinity and salt water salinity would kill most fish if they were placed in the opposite environment.  Salt is an excellent preventative though and should be used in most fish tanks... as a preventative and also as mild form of treatment.  There is a lot of research and articles out there about salt baths... I have never found them to be of great benefit... mostly because we have medication that will do a better job without all the stress to the fish. Stress is one of the main killers of fish and a sick fish is not going to tolerate much more stress before it dies.  I hope this helps.... dave