I haven't had a problem with salt with my plants, but check and make sure it's okay for your other fish. (Mollies love salt, it's not a problem for them at all.) But if you have catfish or other scaleless fish or snails you may want to put them into a separate quarantine tank. You can do salt dips for it in a separate container. Two tablespoons per gallon, non-iodized salt (kosher salt is easiest to get, it's non-iodized and doesn't have non-caking ingredients added). Make sure it's appx the same temp as the tank, dissolve the salt completely, put the fish in for a half hour, watching for signs of distress, then put the fish back into the tank or a quarantine tank.