Conditioning salt is used to help reduce stress in fish, enhance their slime coat, and help with gill function. Stress can be caused by disease, new fish in the tank, being put in a new tank, fluctuation in water temp., or simply water changes. Stress can also cause illness in the fish if it is stressed too much for too long, just as in people.
Here is a quote from Drs. Foster and Smith's website...
"...Freshwater Aquarium Salt serves as a general tonic and stress reducer for freshwater fish. During disease and stress, healthy gill function of fish is disturbed. This can lead to the loss of electrolytes through the gills (sometimes called osmotic shock), reducing the intake of oxygen and release of carbon dioxide. Freshwater Aquarium Salt replenishes natural electrolytes and promotes healthy gill function. Temporarily blocks the toxic effects of nitrite to freshwater fish until water quality improves. Made from evaporated sea water – contains no artificial additives, sugar, or artificial color and will not change pH. Use Aquarium Salt with tropical fish, goldfish, and koi but should not be used as a substitute for marine aquarium salt. 1 Tbsp for every 5 gallons of water."
I always have salt in my betta's tank because of the frequent water changes and lack of heater, which both cause him stress, but he's always happy, active, and has beautiful coloration, in part I believe to the salt treatment. So salt is a definite plus for fish. I should say though, if it is a larger tank (mine is only a 1 gallon
) the only time you should probably salt the water is when the entire tank is sick and after water changes, otherwise just use the salt in your QT/Hosp. tank.
Hope this helps
