[hail_sniper]

true, it takes away essential minerals that fish need to survive, but that really only occur in FW the being because salt already contains those minerals and many more thus replacing the needed minerals removed from the process of filtration, if i remember right salt has everything fish need to live, and if i am guessing correctly is why people add rock salt to fw tanks where their fish are a bit sick so the salt may be able to help them "revive"