Can ich become immune to salt? I was wondering because I am treating my tank with the heat and salt method. Since it's 125G, I want to do it slowly. Over 3 days total I now have 2tsp. of salt per gallon and everyone seems to be doing fine. Since I took 3 days for the fish to slowly get used to the salt, will ich become used to it as well? I want to kill off these little buggers. I don't have many but I wanted to catch it before it really took off.