looking at the sticky for salt it says:
"Finally, a light solution of 0.01 to 0.2 percent salt may be used as a permanent treatment in recirculating systems. Such levels are quite effective in eliminating single-cell protozoans. Most fish can tolerate prolonged exposure to salt at these concentrations; however, tetras and fish that navigate by electrical field (e.g., elephant nose) should not be maintained in salt."
ok, so what is .01 percent? What is the table spoon per gallon ratio there?
In another post on Ich it says to do 2 teaspoons per gallon. Seems a little high for me unless dealing with cichlids.