aquarium salt as preventative?

Question
currently have a 55gal. with 5 german blue rams, 3 rainbow cichlids, 4,otocinclus.one rubber lipped pleco ,one clown pleco,one raphael catfish,and one small appox. four inch discus.tank is aerated with emperor 400,two 300watt heaters temp.at constant 84 degrees,ph 7.4 ammonia and nitrites at zero.oh ,also have two bolivian rams which may have introduced ich. my fault for not quarantining them. Ido not wish to add chemical to treat ich if aquarium salt will work .problem is not bad yet just one or twq white specs on tails of bolivian rams.tank has been without problems for almost two years. how much aquarium salt and how often should it be added?for 55 gal. LFS says 1 tablespoon per 10 gal? so i added 11 tablespoons three days ago. Iam due for my weekly 20 percent water change in 3 days and dont know whether to treat 10 gal during water change or wait to add salt the following week. Ihave medicine on hand but i would prefer to use it only as a last resort.

Answer
Hi Leland:  While aquarium salt works somewhat on fish disease it can be use more as a preventative measure. If your fish have ICH then you will need to treat it with medication because ICH will cycle through your tank and keep coming back. do a 25 percent water change today and then add the medicine.  Change 20 percent of the water thereafter on a weekly basis until the infection is gone.  If you have further questions please let me know... Dave