10% liquid Chorine "Shock" is really just 10% bleach (it usually is actually a little higher). Regular bleach is 5.25%, "Ultra" (now the standard) is 6%.

What's the other 90%? Salt water! Yup! Bleach is made from brine (saltwater) as the formula for salt is NaCl...Sodium Chloride. So don't worry about it. If you use nothing but bleach/Liquid Chlorine for 10 years you still wont approach the salt water levels necessary for a pool that uses Salt Water Chlorine Generation (SWG,or SWCG).