Pickling salt- ice cream salt-water softner salt-fresh water aquarium salt- pretty much all the same thing. I have even used regular iodized table salt with no ill effects. But most will say iodized is not good. And you want to add 1 table spoon full for every 5 gallons of aquarium water. The bacteria that causes ICK can not live in the low salinity that the salt creates, so they die. It is also a good idea to raise the temperature of the tank up to the maximum that the fish can have so that the ick's life cycle is quicker. There are many more benefits to using salt, this is just one.