Jesus Christ on a pogo stick. Are you seriously that stupid? Is English your second language or something, and that is why your reading comprehension is so poor? Your fish have ich. I give you a clearly visible link to an ich treatment article that tells you everything you want to know about ich and its treatment, and some stuff you might not want to know, and yet, your question is, “…should I try adding some salt?” NO, dumbass, you should NOT try adding some salt. You shouldn’t “try” anything; you should just do as you’re goddamned well TOLD, which, if you’d READ THE FUCKING ARTICLE LIKE I TOLD YOU, you would know includes:

Do not add salt. Salt at levels commonly used in freshwater aquariums will not help to cure your fish of Ich. Salt is for saltwater or brackish water tanks. Treating Ich in saltwater, brackish and pond environments is outside the scope of this article.

Now…stop asking stupid questions and start following instructions, and maybe–just maybe–we can get these ordinarily very hardy fish healthy again before you kill even more than you have already. Dumbass.