Try drsfostersmith.com I looked it up again and since we are trying to accomplish brackish not salt water you should be fine with aquarium salt. Increase it gradually tho. Don't shock the fish. 1 tablespoon per 5 gallons. To start. That is to maintain healthy FW fish. Me personally I would add 1 tablespoon per 5 gallons once a week until hydrometer says 1.00 stop For a week to let them acclimate. Then continue to 1.08 , 1.10 +/-
Just remember to test water and condition on water changes. WC do not remove salt. So you have to add salt to water and make it the same Salinity before it goes in the tank. Get a hydrometer !!! To help get a piece of live rock, has beneficial bacteria in it for SW tanks. Can't hurt
Just a word of caution.