Why Aquarium Salt?

No, you are not turning your tropical aquarium into a marine habitat. Aquarium salt is sea salt -- not table salt (iodides are toxic to freshwater fish). Hardware stores call it Solar Salt and sell it in 50 lb. sacks. Most pet stores carry it, in much smaller quantities. :-)

Aquarium salt is a water conditioner (one of many!) that reduces outbreaks of Ick (a parasite), helps prevent bacterial and fungal infections, enables a fish's gills to work better and puts back some of the natural electrolytes our water treatment plants remove. When my Black Ghost Knifefish became ill and was losing his slime coat, the first thing I did after gravel vacuuming was to add salt.

The usual dose is 1 tablespoon (15ml) of this salt for every five gallons. Assuming I perform a water change by gravel vacuuming my aquariums every week, I probably add more salt once every two months.